|Numbers Aren't Behaviours And They Can't Tell You How You're Doing|
If you're ever curious about how you're doing, those numbers aren't capable of telling you. Sure, the numbers to a degree reflect your efforts and choices, but they aren't in and of themselves those things.
Given what I do day in and day out, I see this most in regard to weight management.
And I tell people, day in and day out, that if they're curious about how they're doing, the answer to that question isn't how much they weigh, how much they've lost, how their clothing fits, how they feel physically, or how they feel mentally. Rather I tell them that if they want to know how they're doing, they have to reflect on what they're actually doing, and whether that's keeping a food diary, minimizing meals out, increasing cooking, securing sleep, reducing liquid calories, whatever their strategies, if they're cultivating consistent change, they're doing well.
That's true with school in terms of going to class, doing your homework, and studying.
It's also true of sports in terms of practice, strength training, consistency, etc.
All this to say, don't confuse numbers with behaviours, and if you're doing all the things, you're doing great, numbers be damned.
|Farm To Cafeteria Canada Offering $10,000 Grants. Should Your School Apply? Details Here!|
When I first heard about Farm to Cafeteria Canada grants I immediately asked if they wanted to write a guest post explaining how they work. Happily Carolyn Webb, the Coordinator of Sustain Ontario’s Edible Education Network, was able to do so.Check out this quote from NorKam Senior Secondary in Kamploops, BC,
“This year at NorKam Senior Secondary in Kamloops, BC, our cafeteria class started a salad bar for a fresh, healthy addition to our regular lunch service. We began this semester by growing our own vegetables, herbs and microgreens in anticipation of improving our cafeteria’s menu selection, and quality and freshness of food.”Would you like to see a similar quote from your school next year?
Or how about these?
“College Heights Secondary School in the Upper Grand District School Board (Ontario) has had a fantastic first year connecting our school to local food and farms, and launching a full salad bar as part of our cafeteria service.”Farm to Cafeteria Canada is offering $10,000 grants that would allow elementary and secondary schools in British Columbia, Ontario, Quebec, and Newfoundland and Labrador to implement a Farm to School program that includes a salad bar meal service.
Farm to School brings healthy, local food into schools, and provide students with hands-on learning opportunities such as growing and cooking that foster food literacy and enable students to make healthy food choices, all while strengthening the local food system and enhancing school and community connectedness.
The Farm to School Movement is growing across Canada. Today more than 1,100 schools and campuses across Canada have identified that they are providing more than 775,000 students with an opportunity to experience Farm to School through school gardens, cooking programs, salad bars and other activities. These schools and campuses estimate they spend nearly $17.5 million annually on local foods. For more information about Farm to School’s growth in Canada check out Canada’s Farm to School map.
For more information about how to apply for our 2018 grant opportunity please visit the Farm to School Canada Grants 2018 page. Applications are due by March 31st, 2018.
For more stories of inspiration from our 2016 grantees visit our Farm to School Canada Grants 2016 page!
|Saturday Stories: Tonya Harding, Pizza Cinnamon Rolls, and Romantic Hunter-Gatherers|
with her interview of Tonya Harding.
Geraldine DeRuiter, in Medium, describes her experiences making Mario Batali's sexual misconduct apology pizza cinnamon rolls.
William Buckner, in Quillette, on the romanticization of the hunter-gatherer.
|Britain's Food Nannies Will No Longer Sell You 1.75L Bottles of Coca-Cola|
And yet there's no outcry from the beverage industry.
You'd think there would be. After all, back when nanny Bloomberg tried to pass his cup size ban - the one that would have forced you to buy two 500ml cups if you wanted to drink the volume of a human stomach (1L) worth of soda at once, the beverage industry bought a full page advertisement in the New York Times to complain about it (that's it up above).
But what about Brits' rights to buy 1.75L bottles of liquid candy? Why no screaming about Britain's fun and freedom stealing nanny?
Because Britain's nanny is the beverage industry. You see Coca-Cola, consequent to Britain's new soda tax, wants to ensure people keep buying plenty of product, and to help ease the tax' sting, they're going to stop selling 1.75L bottles (which incur more tax) altogether.
So the next time you're tempted to shout about the nanny state when someone like Bloomberg proposes a new policy designed to encourage decreased consumption of junk food, remember, you already live in a nanny state.
The food industry is your nanny.
(originally posted in response to Philadelphia's similar plan)
|Body Weight Set Points. Sociology, Or Physiology? |
And regardless of the mechanism, what appears to be true is that people tend, following weight loss, to regain the weight they've lost, finding themselves right back where they'd started.
As to the mechanism, there are many theories (including a cool new one that was explored in mice which Dr. Sharma covered last week), but the one that I tend think carries the most weight is sociological, not physiological, in that when we give up on our temporary diet and lifestyle interventions, we revert back to the lives we had been living prior. Those lives, for better or for worse, are comfortable and automatic. They include our dietary likes and dislikes, our cooking skills, our life's responsibilities, the number of meals out we regularly eat on our own, with our families, and with our friends, our sleep patterns, our activity levels, our treats and indiscretions, and so much more.
They also include the same average number of daily calories that they always did.
So why would it be surprising that when we quit our diets and return to all of our normal patterns (and calories), that our weights tend to head back to where they started?
All this to say, aim for the healthiest life that you can actually enjoy, as if life's merely tolerable, you're less likely to stick with it.
|Saturday Stories: Siddhartha Mukherjee², and a Tea Party Friendship|
his poignant and incredible piece about his father's death.
Siddhartha Mukherjee in The New York Times Magazine, with his description of what happens when a clinical trial fails.
Stephanie Mencimer, in Mother Jones, with her tribute to her late Tea Party friend.
|When Diet Meets DNA: A Premature Love Story|
For those of you who aren't familiar with doctoral student Kevin Klatt, he's one of the most thoughtful balanced voices on nutrition around. This fall, I noticed Kevin chatting on Twitter about the realities and limitations of nutrigenomics and invited him to write a guest post on same. Happily, he agreed, and as with all of Kevin's writing, his piece is deep, thoughtful, and fair. If you're considering spending money on genetic testing as related to diet, please read his terrific overview before shelling out your hard earned cash.Tis the season for New Year’s resolutions and this year, buying a diet plan based on your unique genetics stands to be all the rage. As genetic/genomic technology has greatly advanced over the past 2 decades, we've seen a number of genetic testing services for you (and for your dog) pop up and they're more than willing to help you live your best life. Genetics test are increasingly marketed to health-conscious folks who want to maximize their nutritional health, promising to give you diet recommendations tailored to your specific genetics. Numerous articles have popped up over the years about 'eating for your genes' and, of course, those who want to eat for their own genes get links to websites that will happily take your cash and send you a diet report (some will even send you the food!) or supplements matching your specific genetics. So...how legit are these?
The science of 'nutrigenetics', or the study of the interaction between genetic variation and dietary needs, is a real, although very immature, science. Researchers have long known that individuals respond differently to different diets and that genetics probably plays a role in this variation. Despite the marketing trope that diet advice is 'one size fits all', inherent to the Dietary Reference Intakes (DRIs), estimated nutrient requirement and intake guidelines published by the Food and Nutrition Board (FNB) of the National Academies of Science, is the notion that nutrient needs vary. The DRIs establish estimated average needs for specific nutrients, and how variable these needs are, assuming the normal distribution pictured below; from there, policy makers and clinicians can assess whether a population or individual is at a high risk of inadequate nutrient intake. Why do individual nutrient needs vary? For a lot of reasons, such as differences in an individual’s growth and development, microbiomes, medications, physical activity levels, and, yes, genetics! The field of nutrigenetics focuses specifically on how certain genetic variants impact nutrient metabolism and affect nutrient requirements.
While these are scientifically meaningful approaches, the interpretation of these gets a bit funky and can lead over enthusiastic entrepreneurs to selling more hype than science. A few things to consider about nutrigenetics research before you go buying a test:
1. Very little of the evidence establishes 'cause and effect' - The types of research that I described above include genotypes into the analysis of studies that weren't designed to primarily look at genotype-x-nutrient interactions. Ideally, we want studies that are adequately designed and powered to test the effect of a genotype-nutrient interaction from the get go. If you include genotypes into the analysis after the study was designed, it increases the likelihood that you observe a significant association only by chance. One can imagine that in a field with 20+ essential nutrients/dietary components that are of interest, an array of measured health outcomes, and now the addition of innumerable genotypes, we can make a lot of comparisons. While these comparisons might generate some nice hypotheses, they are at a high risk of being false positives.
What the field needs a lot more of are randomized controlled trials where individuals are genotyped before an intervention ('a priori') and then randomized to a dietary intervention. This allows for much stronger causal inference that a genotype does indeed have an effect. We also need repetition of these trials across diverse ancestries - because of the way genes are possibly inherited, genotypes that we think are causal may just be very close to the actual causal genetic variant on a chromosome! To date, there is one pretty good trial that looked-for individuals with the MTHFR who had 2 copies of the variant ('TT') and then randomized them to a riboflavin supplement. We need a lot more of these before we get too excited about genotype-based dietary recommendations.
2. Individualized isn't so individual - The philosophy that often goes along with genotype-based diet advice is that it moves nutrition beyond the ‘mean’ and really gets to the individual. While a fun marketing line that has led to ‘precision’ everything, the reality is a bit bleaker. Genotypes might sound super ‘individual’ but they really just represent subgroups of the population; similar to the way that we already give nutrient recommendations tailored to specific sub-groups of the population based on age, sex, and life stage, the science of nutrigenetics only refines our educated guess at your nutrient needs, it doesn’t define it. Furthermore, as mentioned above, a lot of other factors can affect nutrient needs, and its unlikely that a single genetic variant will be the only reason that individuals differ in their needs.
3. Effect Size - Popular discussions about 'eating for your genes' that have increased the hype surrounding nutrigenetics are not often concordant with the reality of the data. Effect estimates found in post-hoc, adjusted analyses are often modest (and causality still remains uncertain). Where the field has seen very large effect sizes of genetics variants in outright nutrient deficiency feeding studies, these studies are not available for the majority of nutrients nor do they apply to people consuming relatively nutrient sufficient diets.
In the case of the MTHFR C677T variant, where there is a substantial body of experimental and human data to strongly support the causal nature of the variant, its impact on nutrient requirements, in this case folate, doesn’t really change much about dietary recommendations. As the Academy of Nutrition and Dietetics noted in their position statement on nutrigenomics, there's not good evidence that having this variant increases folic acid needs higher than the current DRIs. To date, we're lacking evidence that genetic variants increase needs so dramatically that they suggest current recommendations are inadequate.
4. Outcomes - The field of nutrition has a pretty good track record of preventing outright nutrient deficiency; much of the population isn't walking around with scurvy. Preventing scurvy, however, is probably not the biggest concern of someone thinking about buying a nutrigenetics test. With nutrition, most folks are interested in the diet that will bring them closest to immortality, and at the very least, one that can help prevent chronic diseases. Unfortunately, it's quite hard to perform large randomized controlled trials (to assess causality) for long enough (to observe meaningful outcomes such as heart attacks) in the field of nutrition, which has led to a lot of confusion about how to best give dietary recommendations based on chronic disease outcomes. Do we put more faith in short term trials while measuring some intermediate marker of disease (like blood cholesterol), or do we rely on big epidemiological studies that can't assess causality and often rely on self-reported dietary intakes. These limitations still apply to nutrigenetics! There's some hope that incorporating genetic variants into current analyses might reduce some of the noise in the data, as seen in the relationship between caffeine and heart attack/hypertension. However, this is largely optimistic, and for most genetic variants advertised today, we lack the confidence to say that changing your diet accordingly will causally impact meaningful outcomes in the same way that we lack this inference from general nutrition data. Alas, immortality remains elusive!
5. Repetition, or lack thereof - I personally think the relationship between caffeine intake, genetic variants, and heart attacks is super interesting and one of the more 'low hanging fruit' hypotheses generated from the field of nutrigenetics. However, to date, we don't have additional studies to support these early interesting observations. Repetition of findings is a key component of an evidence-based recommendation. While companies selling you a genotyping kit might be more than happy to hype one promising early study from the field of nutrigenetics, keep in mind that the science in the field is generally super premature. We generally don't have numerous publications showing similar results across a number of studies and populations. It's quite easy to get super excited about genotypes that show promising relationships that sound biologically plausible, but without seeing that relationship often, across several populations, dietary recommendations are nothing short of rushed.
6. But isn't it motivating? #EatForYourGenes. For the clinicians out there, the science of whether genes affect metabolism and your nutrient requirements is cool but what we may really want to know is the likelihood that communicating that genetic information will lead people to eat a meaningfully better diet. Good science and good intentions coming from the nutrition community have tried to get folks to eat fewer calories, less fat, less sugar, more fiber, etc, but this hasn't always translated so well. With personalized nutrition, the field runs the risk of not only communicating recommendations in a way that might not lead to behavior change, but also having folks $pend a bunch of $ on genetic test$ that don't yield meaningful result$. The last thing the field of nutrition needs is another reason for the public not to trust it.
Where's the evidence at on this? The most recent Cochrane Review assessing the impact of conveying genetic information on behavior included 2 diet studies; the Cochrane review estimated a positive effect of conveying genetic information on changing self-reported diet intakes after pooling data from 2 studies. Before you get too excited, these data hardly support buying a genetic test to tailor your diet. The 2 included studies assessed whether conveying mutation information to individuals with familial hypercholesterolemia (FH) would lower fat intake, and the impact of self-reported changes in general diet after receiving information about ApoE genotype in adult offspring whose parents developed Alzheimer's. Neither of these populations are very relevant for the average person looking to get nutrigenetics testing, nor are their self-reported outcomes that impressive. Another systematic review and meta-analysis including 7 randomized and quasi-randomized controlled trials of nutrigenetics interventions on self-reported diet found no significant effect of the intervention.
Since the publishing of these meta-analyses, the Food4Me study was published, a large multi-centre trial where 3 levels of personalized nutrition (compared to 1 generalized diet) advice were provided, with one level including genotype information; the study reported no benefit from the genetic information arm (though the statistical analyses to determine this aren't shown) on total diet scores. A sub-analysis of this study also looked at whether the personalized nutrition advice would improve adherence specifically to a Mediterranean diet score, finding small added effects of genotype on overall Mediterranean diet adherence, an effect driven largely by an increase in tomato sauce consumption. Before you get too excited, we are talking incredibly small effect sizes here: increases of .25-.43 on a 14 point scale. Translation: letting participants know that they have/don't have 5 nutrient-related risk genotypes leads to a clinically meaningless, marginally significant effect on Mediterranean diet score in a secondary analysis of a large trial. Most folks advocating for nutrigenomics testing aren't going to convey the reality of the data to potential consumers. When the clinician digs a bit deeper, it becomes hard to recommend testing to induce motivation in even the most stubborn of clients with heavy wallets. This area also hasn’t thoroughly investigated the flip side in the real world of direct-to-consumer genetic testing – if I don’t have a genetic variant that increases risk, am I less likely to make a certain dietary change? Even if communicating genetic risk leads individuals to make dietary changes, most studies have not assessed whether communicating a lack of genetic risk runs counter to eating a diet in line with current guidelines.
Conclusion: My overall takeaway on nutrigenetics/personalized nutrition -- come for the science, but don't stay expecting to get a super prescriptive diet sent from the DNA gods. We still don't know most of the factors that go into telling what your specific individual nutrient needs are and the available evidence doesn't support the idea that you'll become super motivated and starting making substantial diet changes. It's always up to you if you're in the financial situation where you can blow $100 on a DNA test and want to see what they tell you that you should eat; i'll always recommend that you go over that with your primary care provider and a registered dietitian. Me? I'm gonna need a lot stronger data before anybody tells me to switch my coffee to decaf or go out of my way to eat more or less of some nutrient.
on twitter, and blogging over here.
|What Are People Eating (And Not Eating) While Following A Low-Carb Diet?|
Today's guest post comes from Dr. Nicola Guess who I invited to write about her recent study which explored what people on low-carb diets were and weren't eating. The tl;dr version? At least according to their dietary recall, they ate more whole foods, and far less in the way of liquid sugars and combination high-fat, high sugars foods (the ultra-processed stuff) - a potentially more sating pattern, and definitely not one that raises any alarm bells. And just an FYI, Dr. Guess is also very active on Twitter and is definitely worth a follow.Carbohydrate restriction can be very helpful in the management of type 2 diabetes, particularly with controlling blood sugar levels. However, there have been several concerns cited about low-carbohydrate diets which I think hinders the widespread recommendation of this dietary approach for management of type 2 diabetes. For example, people might be limiting nutrient-rich foods such as fruits, vegetables and pulses. Others might be consuming a very narrow range of foods such as diets characterised by sausages, burgers and butter, with the occasional fried tomato thrown in. Despite the apparent popularity of low-carbohydrate diets, I realised that outside of clinical trials where the diet is prescribed by researchers, very little is actually known about what foods people eat when restricting dietary carbohydrates.
I therefore sought to examine this question by using national dietary surveys in the UK. Earlier this year I examined the National Diet and Nutrition Survey and found that people on a reduced carbohydrate diet (fewer than 40% of kilocalories from carbohydrate) consumed more red and processed meat, butter, oily fish and vegetables, as well as a lower consumption of soft drinks and pulses than people on a higher carbohydrate intake. I could not examine the intake on a low-carbohydrate diet (of which a suggested definition is fewer than 26% of calories from carbohydrates) because only 15 people out of 2263 followed this pattern.
Fortunately, the UK BIOBANK offered the opportunity for me to examine this question in a larger dataset. The UK BIOBANK is a huge population study in the UK which has collected comprehensive demographic, biochemical and lifestyle data in over 500,000 people. Dietary data was collected using a short food frequency and dietary habits questionnaire on the first visit. This basically asked how often people have different types of meat, oily fish, fruits, vegetables and alcohol, and also what type of spread, cereal and bread people consumed. In addition, a 24-hour dietary recall was completed on up to five further occasions. A 24-hour dietary recall asks the participant what food or drinks they consumed over the previous 24-hours, including the portion size of each food or drink consumed.
Using this dataset I was able to compare the dietary intake of people consuming fewer than 26% of kilocalories from carbohydrates to those consuming 45% or more. Confirming the findings from my earlier study, I found that a low-carbohydrate dietary pattern was associated with a significantly higher intake of red meat, oily fish, nuts and seeds but fewer fruits, vegetables and pulses compared to the normal carbohydrate group. In general the consumption of nutrient-rich foods such as nuts, seeds, oily fish and pulses were low in both groups. However, most striking was the difference in the intake of high-sugar, high-fat foods and snacks such as doughnuts, biscuits, cakes, pastries and ice cream. People in the normal carbohydrate group reported a much higher consumption of these foods (a median of six across the five dietary recalls) compared to the low carbohydrate groups (a median of zero!). This mirrored a result from my earlier study - that total carbohydrate restriction is associated with a preferential restriction of foods high in added sugars - a dietary change almost certainly likely to improve health outcomes.
The other striking finding was how few people actually reported a dietary intake consistent with a low-carbohydrate diet. Out of over 210,000 people who had completed dietary data, only 444 had a low-carbohydrate diet as defined by fewer than 26% kcal from carbohydrate. 1953 people reported consuming less than 130g of carbohydrate per day, which is another definition used for a low-carbohydrate diet. In an earlier study in the US, out of over 10,000 people in the Continuing Survey of Food Intake by Individuals, only 412 reported consuming a diet with fewer than 30% kilocalories from carbohydrates. There could be many reasons for this. Potentially, these types of dietary surveys might attract people who are engaged with conventional health advice, and therefore more likely to follow the type of diet recommended by national guidelines. Another reason may be that a low-carbohydrate diet is difficult to follow for most people. It’s worth mentioning that the low-carbohydrate groups had a higher BMI in each of the three dietary surveys I mentioned above. It’s possible that people with a higher BMI were following this diet to try to help them lose weight, but the low overall number reflects the difficulty in sustaining this diet long-term.
A limitation of our study is that we cannot tell whether people were intentionally following a low-carbohydrate pattern. Therefore I next plan to follow people prospectively as they adopt a low-carbohydrate diet. I hope this research helps us understand what foods people consume on a low-carbohydrate diet (especially people on a low-income) and can aid us in offering dietary advice to people wanting to follow this dietary approach.
Shafique M, Russell S, Murdoch S, Bell JD, Guess N. Dietary intake in people consuming a low-carbohydrate diet in the UK Biobank. J Hum Nutr Diet. 2017 Dec 13.
Guess N. Dietary intake in people consuming a reduced-carbohydrate diet in the National Diet and Nutrition Survey. J Hum Nutr Diet. 2017 Jun;30(3):360-368.
Kennedy ET, Bowman SA, Spence JT, Freedman M, King J. Popular diets: correlation to health, nutrition, and obesity. J Am Diet Assoc. 2001 Apr;101(4):411-20. Review.