Movember

It's Movember, and so I think that it is only fitting that I dedicate a post to prostate cancer. As it so happens, the latest update on the SELenium and vitamin E Cancer Prevention trial (SELECT) was recently published [1]. An excellent summary of this study by it's primary funder (provided $129,687,000 - ouch), the National Cancer Institute, is available online here.

Before reviewing the study, lets hop in the DeLorean and head back to 2001. It was a much simpler time - no Facebook, HP and LOTR were just hitting the big screen, Jean Chretien is PM, and Dan Cloutier is the Canuck netminder. The incidence (# of new cases) of prostate cancer has increased dramatically in the last decade, which is mainly attributable to increases in screening including the widespread availability of the prostate-specific antigen (PSA) test. Interesting side note, the routine screening for prostate cancer using PSA is highly debated today amongst expert organizations (for: American Urological Association / American Cancer Society; against: U.S. Prevention Services Task Force) [2]. Back in 2001, there is a growing body of evidence that dietary antioxidants may be able to prevent certain cancers. Two clinical trails, neither designed to measure prostate cancer, are published indicating a large benefit of supplementation with vitamin E [3], and selenium [4] for the prevention of prostate cancer:

[3] The Alpha-Tocopherol, Beta-Carotene (ATBC) trial was designed to evaluate the effect of supplementing antioxidants, vitamin E (aka alpha-tocopherol) and beta-carotene (precursor for vitamin A), on lung cancer prevention in male Finnish smokers 50-69 years old. Interestingly, this study [5], along with the CARET study [6], are often cited as warnings against the use of antioxidants supplements. However, further analysis of the ATBC study found a 36% reduction in prostate cancer incidence in the group receiving vitamin E.

[4] The Nutrition Prevention of Cancer (NPC) study is a secondary prevention study that was designed to evaluate the effect of selenium supplementation on preventing the recurrence of basal or squamous cell carcinoma (skin cancer) among patients referred to dermatology centers in the U.S. with non-malignant skin cancer. Although there was no benefit for preventing skin cancer recurrence, the group receiving selenium had 0.35 times the risk (2.85-fold decrease in risk) of developing prostate cancer.

Overall, the data at the time suggested (quite convincingly) that both vitamin E and selenium supplementation might be able to reduce the occurrence of prostate cancer. I'd like to take a moment to acknowledge that my previous sentiments regarding the paramount importance of coming up with a catchy acronym for research studies are well supported in this literature - SELECT, ATBC, CARET, NPC.

Flashback to the present, the SELECT study. It was a 2x2 clinical trial of selenium (200 mcg/d) and vitamin E (400 IU/d), meaning that participants were randomly allocated to one of four treatment groups:

1 - selenium and placebo

2 - vitamin E and placebo

3 - selenium and vitamin E

4 - placebo and placebo

This was relatively large trial, including 35,533 older men from US, Canada and Puerto Rico with 2,279 incident (new) cases of prostate cancer. In 2008, a preliminary analysis of the data indicated that it was very unlikely that a significant beneficial effect of supplementation would be detected, and that there might even be an increased risk of prostate cancer in the group receiving vitamin E. Consequently, subjects were instructed to stop taking their supplements, but were invited to continue to participate in monitoring. Last month, they published an updated analysis that including the time since stopping supplementation, and noted the following:

This graph depicts just the raw data - how many men were diagnosed with prostate cancer (total) in each of the groups. By year nine, the number of men with prostate cancer was lowest in the placebo group (n = 529) and highest in the vitamin E group (n = 620). After the initial release of data in 2008 (approximately year 6 in the above graph), the number of men still participating in the study decreased (year 6 = 19,218; year 7 = 12,129; year 8 = 5,483; year 9 = 186), which introduced bias into the results. This is best demonstrated by looking at the annual risk of developing prostate cancer by year:

As can be seen, for most years, close to 1% of the men in the study developed prostate cancer with the exception of year 9, where apparently there was a prostate cancer outbreak (not really). If we remove the 9th year from this table, it is possible to look at the annual risk by groups more closely:

As you can see, the risk of prostate cancer by group was similar each year with a slight, but statistically significant greater risk in the vitamin E group when adding all the years up. Overall, men receiving vitamin E were found to be 1.17 times more likely to be diagnosed with new cases of prostate cancer. This increased risk may sound like a lot, but it translates into an additional 1.6 new cases of prostate cancer annually per 1,000 men taking 400IU/day of vitamin E.

So why the disappointing results - the easiest and perhaps most accurate response is we don't know. The study populations of the previous clinical trials that showed considerable promise were smokers and individuals with skin cancer, both conditions that may be related to oxidative stress that benefits from antioxidants. Another possibility is that the previous research findings were false. In research, the convention is to allow for a 5% probability that the results could have happened by chance alone - when data mining a study like the ATBC trial, looking at hundreds of different outcomes that weren't part of the initial research question, it is reasonable to assume that statistically significant relationships may appear by chance or bias alone. For example, one of the initial findings from the SELECT study in the 2008 analysis was that participants in the selenium group trended towards increased risk of developing diabetes. This will undoubtedly be cited as a reason for future research into the possibility that selenium supplementation may increase the risk of diabetes in older men.

Perhaps the most compelling explanations for why vitamin E appeared to increase the risk of developing prostate cancer was the dose used. The dose was 400 IU/day, which greatly exceeds the amount of vitamin E that is estimated to meet the needs of 98% of healthy adult males (22.4 IU/day). The 'more is better' approach to nutrients is pervasive in our society, yet these mega-doses beyond what is normally found in food are not without risks. Below is a classic diagram relating to essential nutrients that most (presumably all) dietitians in Canada are quite familiar with:

This U-shaped curve describes the relationship between intake of an essential nutrient and health. I use the term "essential nutrient" quite deliberately because only essential nutrients results in adverse events at inadequate intakes. It may surprise some to learn that many of the nutrients that are advertised on food labels (ie. plant sterols for cholesterol lowering) are not required in the diet for health. These nutrients are more akin to drugs, and are the driving force behind the ever-growing nutraceutical (aka pharmaconutrition) and functional food industries.

The SELECT study seems destined to serve as another cautionary tale for supplement users. Attempts to identify and encapsulate the roughly 5,000+ bioactive phytonutrients (nutrients found in plants), and determine who will benefit from supplementation and at what dose will surely keep nutritionists such as myself occupied and employed for a long time to come. Until we know more, I would recommend that healthy adults aim to get their antioxidants from food with the appreciation that more isn't always better.

[1] Klein et al. Vitamin E and the risk of prostate cancer: The selenium and vitamin E cancer prevention trial (SELECT). JAMA 2011; 306(14): 1549-56.

[2] Hoffman RM. Screening for prostate cancer. NEJM 2011; 365: 2013-9.

[3] Heinonen et al. Prostate cancer and supplementation with alpha-tocopherol and beta-carotene: Incidence and mortality in a controlled trial. JNCI 1998; 90: 440-6.

[4] Clark et al. Effects of selenium supplementation for cancer prevention in patients with carcinoma of the skin: A randomized controlled trial. JAMA 1996; 276(24): 1957-63.

[5] Heinonen et al. The effect of vitamin E and beta-carotene on the incidence of lung cnacer and other cancers in male smokers. NEJM 1994; 330: 1029-35.

[6] Omenn et al. Effects of a combination of beta-carotene and vitamin A on lung cancer and cardiovascular disease. NEJM 1996; 334: 1150-5.

The Industrial Food System

The future of the food system is probably not something that is going to keep most Canadians up tonight. Thanks to technology, cheap inputs, externalization, and the economies of scale, the average Canadian spends only a small fraction (~10%) of their income on food, and consequently is content to live in blissful ignorance of where their food comes from and how it came to be in their grocery store, restaurant, etc. By isolating ourselves from the food system, we place the responsibility for our food supply in the hand of a relatively few large corporations, aka the food industry. For most commodities and services, the conventional capitalistic model, while morally heinous, functions. Although the current entrepreneurial approach to the food system appears to be working well, it is really a matter of perspective.

So how is the food industry different, and why is it deserving of special consideration? The simplest and most obvious reason is that that we all dependent upon a steady supply of food for our continued survival as individuals and as a species. Another, and perhaps more important point, is that the demand for food as a commodity is relatively finite. According to Statistics Canada, the Canadian population has grown less than 5% in the last five years. This inherent limitation of the food system expansion, the stomach factor, does not exist in other industries.

The stomach factor places an incredible amount of strain on food companies to find other ways to increase profits, which they must do. The options include, but is not exclusive to:

1. Get people to eat more
2. Increase their share of the market
3. Sell their products for more
4. Produce the products for less
5. Find other uses for their products

All of these options are potential threats to food security,

a basic human right that is upheld when all individuals in society have access to safe, nutritious and affordable food that is culturally-appropriate, sustainably-produced (ecologically, economically and socially), and is obtained in a manner that upholds the dignity of the individual

It goes without saying that food security is something that the Canadian government does very little to guarantee (a topic for another day).

1. Get people to eat more:

This has been a "big" success. According to a Statistics Canada report, estimated per capita calorie consumption rose ~1-3% each year between 1993 and 2003; however, a more recent report indicates that this trend has appeared to plateau since then. The success of this method is apparent by our expanding waistline and diminished health. I recently shared a case study of a 2-year old child that was consuming ~3,000-4,000 kcal/day with consequent liver disease. Sadly, the up-and-coming generation of increasing obese children is a real boon for the food industry who actually can measure profits in pounds. Not only will they likely require more calories, they will lend support the "niche" market of weight loss products in their almost futile attempts to look like _______ (insert celebrity name).

The burden of their success is that obesity is now on the radar of most people, and serious efforts are underway to stigmatize overeating, limit portion sizes, and make people more calorie-savvy. It is possible that the simultaneous attempts to increase physical activity (if successful) could help to curb the decreases in food consumption related to living healthier. Another way around this problem is to alter the composition of the calorie-providing nutrients in food to make it so we can't absorb them (aka fat and sugar substitutes). The added advantage of this approach is that the corresponding products can be sold for more - nothing like having your Splenda cake and eating it to.

2. Increase their share of the market:

Ultimately, it is difficult to know for sure whether this will be a good thing or a bad thing. If people start consuming more fresh fruits and vegetables at the expense of convenience foods, it would be wonderful. However, I cannot really remember the last time that I saw an advertisement for broccoli. This is partly because there isn't a lot you can do with fresh broccoli to increase value (pre-chopped for convenience?), making it a poor investment for food manufacturers. Yet, this doesn't correspond to a cheaper, more competitive product that is able to dominate the market. As most people have become aware, the cheapest foods are often those that are mass produced with excessive inputs, and are heavily processed and packaged. These products maintain the lowest price in spite of the costs related to manufacturing and advertising. This paradox is made possible by government subsidies, which permit the sale of certain crops, those that drive the food manufacturing industry (mostly corn and soy), at less than the cost of production. With all foods lobbying for position in our stomachs, when a select few crops start to dominate, our food supply loses its diversity. This has implications for both the sustainability of the food system and the nutritiousness of the food supply. One of the tenets of healthy eating is to eat a variety of foods - this is meant to decrease the likelihood that a nutrient is deficient and/or provided in excess.

A related battle is between food we prepare ourselves and that which we eat outside the home. If a greater proportion of the food was prepared by ourselves from scratch, it would undoubtedly be healthier for us and better for the environment. Again, your stove doesn't advertise, but the restaurant industry that would like to increase its share of the market will, and convincingly. We are so convinced that we consume the majority of our meals outside the home. The downside of this is that, unlike in your home, the restaurant industry wants you to eat more of their food, and will attempt to accomplish this by increasing portion sizes and/or providing incentives for eating more - would you like to increase that to a large for just 25 cents more?

Assuming that the proportion of the food market occupied by convenience foods and restaurants continues to increase, the problem will propagate itself by increasing their political clout and nefarious advertising, and perhaps most concerning, by reducing our self-efficacy for meal preparation. As we lose the ability and confidence in preparing meals from scratch, we become more dependent of the food industry to feed us, and relinquish our control of what goes into our food. The current excess consumption of salt is just one example of an additive that we are unlikely to use so liberally in meals prepared at home.

3. Sell their products for more:

This has typically been accomplished by adding value to products, usually in the form of nutritionism and/or convenience. Unfortunately, it is usually the least healthy products that have the most perceived value, and are able to be sold for more. For example, adding fish oil to sugar-sweetened yoghurt and advertising it as important for a child's brain development. Sometimes the added value is nothing at all. Most recently, I bought some raison that are "cholesterol-free". For those who aren't aware, no plant-based food contains cholesterol, but it certainly sounds good.

Another interesting approach, which I have noticed more often, is providing low-calorie (smaller) versions of products for the health conscious consumer. My favorite is the 100 kcal chocolate bars that are sold for almost the same price as the regular chocolate bar, although the 100 kcal yoghurts are a close second. I'm guessing somewhere in the proprietary world of research there was a study demonstrating that consumers viewed 100 kcal as being a healthy snack amount. Either way, I suspect that these smaller portioned products that are able to be sold for almost the same price as their larger counterparts are going to become more pervasive in our food supply in the years to come.

4. Produce the products for less:

Cost-saving measures are almost never going to be beneficial for all involved. Attempts to streamline agriculture processes have resulted in the current landscape of massive monocultures and factory farms, both of which are vulnerable and generate large amounts of wastes. They are made vulnerable by both a lack of genetic diversity, but also by the fact that should the inevitable happen (food borne illness, mad cow disease, etc.), literally millions of pounds of food need to be pulled from supermarket shelves. Case in point, in 2008, 143 million pounds of ground beef was recalled following an animal cruelty scandal at the slaughterhouses. That same year, several lives were lost, and over a 1 million pounds of meat was recalled following the listeria outbreak from Maple Leaf. While the likelihood of these events may be similar in a small operation (unlikely), the consequences are greatly reduced.

Probably the most effective way to reduce the cost of production is to increase biomass disproportionate to the increase in cost, which is made possible in conventional agriculture thanks to cheap inputs. However, as the cost of energy increases, so does the cost of conventional agriculture, and the amount of government subsidies needed to maintain the current system of cheap, processed foods.

5. Find other uses for their products:

This relatively recent venture is mostly limited to the crops that are so well subsidized that other industries want to take advantage of the cheap inputs. In particular, the deconstruction of crops such as canola into basic chemical components allows us to do almost anything with it, most notably producing plastics and fuel. This new market has been great for producers as the increase demand drives up the price. However, given the limited amount of arable land, this trend towards growing crops for non-food uses places greater strain on the available land and food industries.

I have discussed 5 ways that the food corporations can continue to thrive in a capitalistic model. Most of these approaches contribute to food insecurity, something that future generations will probably have to deal with. It is unlikely that we can stop the food industry machine as too much of our food supply is tied up in it. However, it may be possible to regain back some of the control that we have lost over our food by simply ensuring that each and every day that majority of things we put in our face are actually food that we prepared. It won't save us money and will take time out of our busy day, but it will be healthier (in most cases), and will provide hope for the future of food.

The YAM CanFoG - Results and Discussion

I am quite pleased to be reporting that the Young Adult Male following Canada's Food Guide (YAM CanFoG) study has be terminated early based on my predefined criteria for a clinically-significant weight loss (+/- 3 lb / 2 weeks). While the study title essentially says it all, for those interested, I have provided the details of my little mis-adventure on a previous blog post: "The YAM CanFoG - Design".

The study objective was to determine if Canada's Food Guide provides the appropriate amount of calories for young men (19-30 years old). My research hypothesis was that consuming only the foods recommended would result in negative energy balance and weight loss. I meant this in the general sense, acknowledging that the diversity in food supply and variability in energy expenditure was bound to generate combinations that would produce a positive energy balance. Indeed, I previously demonstrated that my 7-day food record included only 50 different food items, but could provide anywhere between 1,205kcal and 3,308kcal per day while adhering to the recommendations for number of servings within each food group.

I decided to start at the beginning, looking at the study that was used to generate the food groups, daily servings and recommendations for food choices in the guide. I reported my findings in the post: "Canada's Guide to Weight Gain?". Briefly, Canada's Food Guide was developed with a focus on nutrition, looking at what model would result in adequate intake of nutrients while limiting the risk of toxicity based on the food choices of Canadians. There were 39 different nutrients variables that needed to be considered in this modeling process:

In addition to looking at these nutrients in each of the 16 age-and-gender groups for the 50 food models being considered, the researchers assessed energy balance. Erring on the side of caution, the researchers compared estimates of energy intake with energy requirements based on sedentary activity level. For most age-and-gender groups (8/12), the median estimated intake was within or below the median energy requirement range.

Overall, the process was transparent and well-designed, and is a useful model for developing and evaluating dietary guidelines for a population. However, there were a few limitations worth noting:

1. Dietary intake of Canadians was derived from the Federal Provincial food and nutrition surveys for BC, Manitoba and Ontario for adults, and Quebec for children.
2. The 500 simulation diets that were used to test each dietary model, while representative of the population intake, may not capture the food choices of the individual.
3. Validation of the dietary model, in particular its interpretation and application by the public, was not assessed by fielding testing in free-living subjects (to my knowledge).

For males 19-30 years old, the median estimated intake of 2,344 was below the median estimated energy requirement range of 2450-2550kcal per day. While these findings support my research hypothesis, given the limitations of the study, further investigation was warranted. To this end, I decided that I should put Canada's Food Guide to the test. Admittedly, I "borrowed" the idea from physical trainer, Eric Briere, who is currently (as far as I know) still following the food guide, and gaining weight.

I first approached this mathematically by comparing my 7-day food record (~2000 kcal/d) with median estimated energy requirements for males 19-30 years old (2450-2550kcal/d). This approach also supported my research hypothesis, but given the numerous sources of variability and error, the only way to be certain was to actually test it out.

It was an n of 1 study, and I was the subject. I'd hardly consider myself to be representative of the average man. At 5'5" and 138.8 lb, I would expect my energy requirements to be below the median range. However, as pointed out previously, my diet is arguably lower in added fats and sugars than the general population, and would therefore provide less calories.

I am pleased to note that compliance with the diet was 100% (no cheating). I also managed to adhere (somewhat) with the recommendations in Canada's Food Guide to obtain at least 30-60 minutes of moderate physical activity every day. My average was 70 minutes/d, although some days I was sedentary (15 minutes of activity), and others I was quite active (up to 150 minutes of activity). This weekend effect depicted in the table below is probably consistent with what most individuals experience who work the standard M-F shift.

I wore a BodyBugg during the experimental period (thank you Dr. Alan Titchenal). Unfortunately, I didn't obtain this device until the afternoon of Day 1. I have provided the values for readers, but excluded it from analysis. My estimated energy expenditure was 2,458 kcal/d (2,151 - 2,790 kcal/d), and my number of steps was 7,000 steps/d (4,607 - 10,359 steps/d).

These findings indicate that I was in negative energy balance of ~500kcal/d for the two weeks of study. Using the 3,500 calories = 1 lb of body weight, I would be expected to lose ~1 lb/wk while following Canada's Food Guide. My actual weight change can be seen below:

As you can see, my weight loss of 3.1 lbs exceeds what would have been expected by the math by roughly 150%. There are several possible explanations for this discrepancy. First and perhaps as likely as any other, we are dealing with relatively small changes in weight, so slight errors in measurements and estimates can have a larger impact. Another possibility is glycogen storage depletion. Our bodies are able to store excess carbohydrate in our diet (~2,000kcal worth) as glycogen. This reserve of carbohydrate provides glucose for cells that need it (ie. red blood cells, brain cells) during periods of fasting such as between meals. Glycogen is a branched molecule that traps water, which partly explains why individuals following low-carbohydrate diets tend to experience a more rapid weight loss early on in the diet. As their glycogen stores become diminished, they lose weight as water (~1:3 glucose:water). My diet wasn't low-carbohydrate (53% of calories), but if I was in negative energy balance of ~500 calories per day, it is reasonable to assume that my glycogen stores may have been slightly depleted.

There are a limitation of my study that I need to acknowledge. I consumed less calories than the estimated median intake derived from the population. It is difficult to account for this difference, particularly given that my range in daily intake (1813-2090kcal/d) was below even the 10th percentile of 2100kcal/d. My diet is compliant with the food guide, leaving me to wonder if this inconsistency is not at least partly related to the use of vague, lenient verbiage such as "select lower fat milk alternatives" in the food modeling.

I am admittedly happy that the experiment was terminated early. Prolonged negative energy balance, even for two weeks, is unpleasant to say the least. It was a great learning experience for me, and has certainly got me thinking, just not about food guides.

Katamay SW, Esslinger KA, Vigneault M, et al. Eating Well with Canada's Food Guide (2007): Development of the food intake pattern. Nutrition Reviews 2007; 65(4): 155-66.

Recipe for Foie Gras - Part 1

In this series of posts, I will be compiling a few recipes for making pediatric foie gras. Like any good dish, there are bound to be regional variations (each with their own take), but I think that a few ingredients will stand out as being important.

In today's post, I will share a very special recipe that was developed in Springfield, Il.

I came across this case study published in Clinical Pediatrics a while ago, and thought that it was quite interesting. The title alone, Non-alcoholic Liver Disease in a Toddler, has a certain 'je ne sais quoi'.

Take 1 white female toddler (27 months old), and add potato chips, cereal with milk (2%), fried eggs and toast with butter and jelly. Allow to sit for several hours. Fold in bacon, chili, hot dogs, cheese, potato chips, macaroni and cheese, canned ravioli (and similar foods) in batches throughout the day. Food should be fried with added butter of grease for maximal effectiveness. Stir in 2 liters of tea sweetened with sugar (~1.5 cups of sugar), 2.5 cups of Kool-Aid, and 3 cups of milk (2%) until smooth. Feel free to add potato chips, candy, pie, cookies and other dessert items periodically as needed until caloric intake is ~3000-4000 calories per day.

Most pediatric foie gras dishes made in the US use Hispanic males ~13 years of age, so this does stand out as an exception, rather than as a defining recipe, but it does provide an idea of how to make foie gras in a hurry if you don't want to wait 13 years.

I joke, but this is hardly a laughing matter. The fact that a toddler is suffering from a chronic illness related to poor diet is an appalling indication of the world we live in. I think many of us would be tempted to defer responsibility for this atrocity onto the parents, but their food choices include many of the most popular items on the supermarket shelves. At some point, we need to accept our share of the blame for allowing the food system and food itself get away from us.

Fishbein M, & Cox S. Non-alcoholic fatty liver disease in a toddler. Clin Pediatr 2004; 43: 483-485.

A Bad Thing

As a science, nutrition can be a little ... confusing (to say the least). I intend to address the reasons for some of this confusion later, but for now I want to write about some of the implications. Most, if not all people, have many ideas about what is and what isn't "healthy". Unfortunately, this is one of those situations where a little information, even if it is the right information, can be a bad thing.

For better or for worse, the landscape of food has been transformed into a jungle full of terrific and terrifying possibilities. We have both figuratively and literally deconstructed food into thousands of chemicals, added a few of our own, and re-assembled them in every way imaginable. Everyone has to eat, but there is simply too much information (and a paucity of evidence) to make an truly informed decision, so we simplify. We dichotomize foods and nutrients in our mind into 'good' and 'bad' based on what we know. I imagine it looks a little something like this:

It is all that any of us can really hope for in the vast and ever-changing food environment, but leaves us vulnerable to food advertising. Food companies are far more interested in your money than in your health. What's more, they are well equipped with a arsenal of impressive sounding nutrients that many consumers likely know little about (fatty acids like DHA, isoflavones like genistein, amino acid derivatives like HMB, and so on). Very few of these nutrients are actually required in the diet, but instead are endowed with drug-like properties and fanciful claims.

Our only shield against this onslaught is the government who have, quite regrettably, taken a pro-business, individual responsibility stance on the issue. The result - supermarkets are chock-a-block full of unhealthy products guised as being wholesome. Most are fairly innocuous such as our breakfast favorites (sugar-sweetened multivitamins with fiber), while others are downright alarming, acting as vehicles for the uncontrolled delivery of drugs. Sadly, the notion that the best products to avoid are those that appear healthy has some merit. A simple, yet elegant solution has been put forth by Michael Pollan:

"Eat food. Not too much. Mostly plants."

This view asks us to embrace ignorance and eat like our grandparents. It's a good premise. If we put aside the little that we know, we are far less susceptible to nutri-fluence. However, I think this ship has sailed. Food and nutrition information is all over the place, and it is not in our nature to ignore it. Furthermore, there isn't much actual food left in the supermarket, and many consumers lack the skills and/or motivation to prepare meals from scratch.

So what are our options. I doubt that we are anywhere close to having nutrition figured out, and I don't think that this successful advertising approach is going to stop anytime soon. All that we can do is make people consciously aware of this ruse so that they are less easily deceived. Perhaps with time, our population will shift from pre-contemplation to contemplation, and we can start to address some of these issues at their source.

Take Home Message:

The presence (good source of omega-3s) and/or absence (cholesterol-free) of single nutrients does not make a food healthy.

The YAM CanFoG Study - Design

If I take one thing away from my experience as a graduate student, it will be that the most important component of any study design is coming up with a catchy abbreviated title. Thus, I am pleased to introduce the Young Adult Male following Canada's Food Guide (YAM CanFoG) Study.

Now that this is out of the way, I am able to provide you with a description of the study itself. For those of you just tuning in, the idea for this study was developed by Eric Briere, a physical trainer that, having never looked at Eating Well with Canada's Food Guide, was disturbed by the number of servings of Fruits and Vegetables and Grain Products that it recommends he consume in a day (8-10 and 8 servings, respectively). For those interested, his video can be viewed here, and a detailed background on why I have decided to embark on a similar experiment can be found on my post entitled "Canada's Guide to Weight Gain?".

The YAM CanFoG study will look at the effect of following the Canadian food guide for one month on energy balance in a young man with low activity (me). To prepare for this, I designed a 7-day food cycle using meals and snacks that I would generally consume, which also adhered to Eating Well with Canada's Food Guide. I then conducted nutrient analysis on the diet using the USDA nutrient database to get an approximation of macronutrient and energy intake. The following table summarizes the analysis:

As you can see, this diet provides ~2000kcal/d with ~100g protein. This intake is below the 10th percentile (2100kcal/d) of estimated intake for my age / gender based on 500 simulated diets following Eating Well with Canada's Food Guide that were published in the paper describing the food guide development. The simulated diets were derived using data on dietary intake form the Federal-Provincial Food and Nutrient Survey from British Columbia, Manitoba and Ontario. One possible (and likely) reason for the discrepancy in my estimated energy intake is that I am choosing foods that are lower in added sugar and fat compared to the general population for which the simulated diets were derived. However, Canada's Food Guide does recommend that "limiting food and beverages that are high in calories, fat, sugar and salt", so my food choices adhere to the food guide well, even if they are atypical.

The primary outcome for this study will be change in body weight. Each week at the same time (Monday morning), I will be weighed using a calibrated electric scale in a blinded manner. I will be wearing the same clothing for the weigh in, and will have attempted to void prior to reduce sources of error. The average of two weights to the nearest 0.1 lbs will be taken a recoded. As a safety measure, weight gain or loss greater than 3 lbs half way through the experiment will be deemed as clinically significant and mark the end of the study.

A major confounding variable when using weight as a primary outcome is physical activity. To control for this, I will be wearing BodyBugg and maintaining a physical activity journal. I am aiming for the 30-60 minutes of physical activity per day during the study as recommended in Eating Well with Canada's Food Guide.

Subject Characteristics:

Age: 27

Gender: Male

Race: White

Height: 5'5"

Weight: ~140 lbs

Occupation: Student

Illness: No known illness

Drugs / Supplements: 4+ coffee / day

Diet Records:

For interest sake, please see tables below to gain an appreciation for the range in macronutrient and energy density of foods within the same food group. These are just for the foods that I am consuming in my 7-day meal plan - all are presented in a per serving according to Eating Well with Canada's Food Guide. Using a worst and best case scenario (and assuming that the subtext of the food guide are just polite suggestions), I could be consuming anywhere between 1,025 calories and 3,308 calories per day.

Thanks for your interest.

Canada's Guide to Weight Gain?

Will following Canada's Food Guide make you gain weight?

This is the question being asked by personal trainer Eric Briere, a question that he intends to put to the test over the next month. While his study design was not apparent from his short video, his hypothesis is clear - he will gain weight. His video has been receiving a fair amount of attention from the virtual community (>100 people Facebook "like" it), and I am concerned about the implications of his experiment.

Eating Well with Canada's Food Guide is an important resource for Canadians, providing basic information on the amount and types of food that should be consumed daily to meet nutrient needs and reduce the risk of certain chronic diseases. Given the dramatic increase in overweight and obesity over the last few decades, it is of the utmost importance that public health messaging be unambiguous and evidence-based. This can be difficult to achieve sometimes, which is understandably frustrating for the public who become increasingly cynical about public health recommendations. The issue of unclear, somewhat vague messages when it comes to dietary recommendations is an interesting one that is worthy of discussion. I will be sure to blog about this later, but for now, I just want you to think about your own diet. It is likely to vary considerably from one day to another, and to have changed over time. Are you able to clearly and accurately describe your lifetime exposure to food and nutrients?

Back to the matter at hand - did Health Canada overlook caloric intake when developing Canada's Food Guide? The answer is no. The paper describing the development of Eating Well with Canada's Food Guide can be found on Health Canada's website. The portion sizes and specific recommendations for each Food Group (ie. eat at least one dark green and one orange vegetable each day) were empirically-derived from Canadian data. The food intake patterns were assessed using 500 simulated diets for each age / gender group. The criteria for energy needs is described below.

"The median energy content of simulated diets should be at or below the Estimated Energy Requirement (EER) calculated for reference individuals using a sedentary level of activity. Measured heights and weights from the Canadian Community Health Survey, Cycle 2.2, were used to determine median height and median normal weight for each age and gender group. These were then used as inputs to the EER equations. A sedentary level of activity was considered most appropriate so that there was no overestimation of requirements."

For most age / gender groups, the median intake was within or below the median EER range with some exceptions (Males 71+, Females 9-13, 14-18, 51-70, 71+). Keep in mind, the median EER range was determined for sedentary persons, and would need to be multiplied by a physical activity coefficient to be compliant with the recommended physical activity levels of Eating Well with Canada's Food Guide (30-60 minutes per day for adults).

As an example, the median EER range for sedentary males 31-50 years old was 2250-2450kcal/d. To convert the EER to align with the recommendations for physical activity in Eating Well with Canada's Food Guide you must multiply the EER by a physical activity coefficient of 1.11. In this case, the range in median EER becomes 2498-2720kcal/d, which exceeds the 90th percentile of energy intake based on the simulated diets adhering to the food guide (2406kcal/d).

This being the said, you might ask yourself why I am worried about Eric Briere's experiment. Based on the data for 31-50 year old males, he is more likely to lose weight than gain it, right? The problem is that he may not be following Canada's Food Guide.

The food intake pattern that became Eating Well with Canada's Food Guide includes the within food group recommendations to "make each food guide serving count...". His suggestion that he will eat 10 bananas a day to meet his fruit and vegetable requirement does not adhere to the recommendation to "eat at least one dark green and one orange vegetable each day".

Moreover, with things like bananas, size matters. Given the diversity within foods like bananas and bagels (his other example), it is necessary to consider the actual amount to obtain an accurate estimate of servings. Portion distortion is common, and explains the misconception that it is difficult to meet daily requirements for Fruits and Vegetables and Grain Products.

That being said, it is certainly possible to adhere to the food guide and gain weight (particularly if you are trying to make that point). Emphasizing energy-dense foods like avocados and nuts within each food group and being sedentary would almost guarantee weight gain.

His study is interesting and has important implications, and I look forward to seeing the results. If his hypothesis is confirmed (he gains weight), it will indicate that we should re-evaluate the methodology used develop Canada's Food Guide, and its appropriateness for use as a public health resource. There is considerable measurement error, both in estimating energy expenditure and predicting energy intake for a population following a food guide, so his research question is a good one. To my knowledge, Eating Well with Canada's Food Guide has not been subject to a validation study in free-living subjects. However, if he does not comply with the food guide, consume his usual foods, and maintain his physical activity level, his study will not address his research question, and the message of weight gain that is conveyed to his clients and the viral community may do undeserved, irreparable damage.

For those of you that are also following his progress, I encourage you to read the paper explaining the development of Eating Well with Canada's Food Guide. For those interested, as I have been looking to conduct an n=1 study on myself, I will be repeating his experiment. Because I am biased, I am going to do my best to remove myself from the equation, and be as transparent as possible.

Using foods / meals that I regularly eat, I developed a 7-day food record and analyzed it using the USDA nutrient database. Throughout the month, I will record my physical activity, and weigh myself every Monday morning, wearing the same clothes, in a blinded manner (someone else will record my weight).

If you have any suggestions of how to further improve this study, please let me know as soon as possible so that I can incorporate them.

Thanks for your interest.

Katamay SW, Esslinger KA, Vigneault M, et al. Eating Well with Canada's Food Guide (2007): Development of the food intake pattern. Nutrition Reviews 2007; 65(4): 155-166.

Inception

It all starts with an idea.

"An idea. Resilient, highly contagious. Once an idea has taken hold of the brain it's almost impossible to eradicate."

- Dom Cobb (Inception)

The idea that obesity can be cured by dieting is a great example of inception. Not in the, Leonardo DiCaprio broke into your subconscious kind of way, but in the sense that the idea has been planted into your mind, and slowly becomes your own. For people raised in North America (and likely elsewhere), the inception begins at a very young age. While it is difficult to pinpoint exactly when it occurs, most 5 year-olds are familiar with dieting for weight loss, the extent of which appears to be related to maternal dieting practices (1). The idea is nurtured with constant reinforcement from our environment, and allowed to develop deep roots, becoming a belief. This presents a problem.

"I think it's better to have ideas. You can change an idea. Changing a belief is trickier. Life should be malleable and progressive; working from idea to idea permits that. Beliefs anchor you to certain points and limit growth; new ideas can't generate. Life becomes stagnant."

- Rufus, the 13th Apostle (Dogma)

The common belief that obesity can be cured by dieting is a problem because it has other implications.

• It implies that there is something wrong with the diets of obese people (for the most part, I agree). However, along with this comes the fallacy that normal weight individuals must therefore have good diets. Importantly, this misconception is not limited to diet - take a look at Homer Simpson for an example of how we view obese people (D'Oh!, Mmmm..., Woo hoo!). This is also the foundation of weight bias, one of the few prejudices that remains socially acceptable today.

• It implies that the cause of obesity is modifiable behaviors. In a superficial sense, I agree. The connection is simple enough to follow - obesity is the storage of excess calories as fat that results from prolonged period of consuming more calories (eating) than you expend (exercising), both modifiable behaviors. This simplistic view of obesity is the basis for the eat-less, move-more approach to its prevention and treatment (seems to be working well so far). This attitude further stigmatizes obese individuals, this time implying that their failure to do anything about their weight reflects a lack of will power.

I would argue that this bleak view of obese people is collective ignorance, and needs to be addressed before we can or will do anything to address the current obesity epidemic. Unfortunately, people can't easily be persuaded to change a belief, a sobering truth that I have come to appreciate in my attempts convince people that the eat-less, move-more paradigm is destined to fail. My efforts, while largely unsuccessful, have not been fruitless. I have learned much about the epistemology (way of knowing) and justifications for this belief, leading me to the concept of inception.

While I would like to blame TV shows like "The Biggest Loser" and convincing testimonials of guaranteed, quick and easy weight-loss diets for planting the idea, it is just as likely that it came from health authorities doing their best to spread the eat-less, move-more message. This view is so pervasive in our society that most people take for granted that it is a fact. Once indoctrinated, our perceptions of reality are skewed to reinforce the belief. Obese people are on our radar, and when we see them buying fast food, or chowing down on a bag of chips, it reaffirms what we know. Add to this the fact that everyone knows someone who has lost weight, and we have all the evidence we need to justify our current view of obesity and obese people.

Before going further, I would like to acknowledge that obesity is related to individual behaviors. There is no doubt that weight-loss is achievable under controlled circumstances. However, this does not mean that obesity is caused by individual behaviors - a small, but important distinction. My rationale for such a seemingly contradictory statement is that I believe that our behaviors are the conduit through which our environment causes obesity, an idea that I will elaborate on in future posts. For now, I would like challenge some of the assumptions related to the eat-less, move-more paradigm.

Dieting is an effective treatment for obesity. Depends on your perspective of effective. I would hardly call a treatment with a success rate of less than 5% effective. These odds are likely to conflict with our own experience (perception) of dieting success (can you name 19 people who failed at dieting for every 1 person that succeeded). What is more concerning is the potential consequences of a failed diet attempt in the other 95% (depression, rebound weight gain).

Obese people have worse diets (and lifestyles) than thin people. A widely-held belief for which the evidence is relatively weak and inconsistent. Take a study of 5,890 Canadian adolescents (11-16yo) for example (2).

% of normal, overweight and obese subjects not consuming F & V daily:

Fruits 64%, 71%, 68% (boys) 58%, 62%, 59% (girls)

Vegetables 61%, 67%, 61% (boys) 53%, 59%, 52% (girls)

% of normal, overweight and obese subjects consuming unhealthy foods daily:

Soft Drinks 27%, 31%, 36% (boys) 17%, 16%, 21% (girls)

Sweets 26%, 20%, 20% (boys) 24%, 18%, 20% (girls)

Potato Chips 12%, 10%, 11% (boys) 7%, 4%, 7% (girls)

Cakes/Pastries 6%, 7%, 10% (boys) 4%, 2%, 6% (girls)

The authors note that it is possible that the failure to find a consistent trend may be due to the fact that "overweight and obese individuals are more likely than normal weight individuals to misreport food intake". I wanted to be sure to acknowledge this possibility, but emphasize that the fact still remains that normal weight individuals have nothing to brag about.

Obese people don't lose weight because they are unmotivated and/or lack will power. I highly doubt this to be the case. Given our attitudes towards obesity and open bias towards obese people, I believe that there is incredible impetus to be thin in our society. The multi-billion dollar industry is proof enough that we are motivated to lose weight. Unfortunately, biology is not on our side - there are powerful mechanisms (leptin deficiency) that are working on both energy intake and expenditure to counteract weight loss attempts (more on this to come).

To be clear, I am not suggesting that obesity is unrelated to lifestyle, or that obese individuals are not liable for their actions. Nor would I argue that we should cease and desist all public health efforts to promote healthy eating and physical activity. What I am proposing is that we adopt a more sensitive and sensible view of obesity as a disease. This is a condition that has serious physical and psychological complications, and we have limited tools for managing it. The argument that people with obesity are somehow reaping what they sow undermines our ability to address the root causes of the condition, and perpetuates the cycle of inception. To overcome this, we need to cast aside this stereotype and see the world through unbiased eyes (best to start with a mirror). Keep in mind, when you point your finger at someone else, there are 3 more fingers pointing back at you.

1. Abramovitz BA, Birch LL. Five-year-old girls' ideas about dieting are predicted by their mothers' dieting. JADA 2000; 100(10): 1157-63.

2. Janssen I, Katzmarzyk PT, Boyce WF, et al. Overweight and obesity in Canadian adolescents and their associations with dietary habits and physical activity patterns. Journal of Adolescent Health 2004; 35: 360-7.