Diet Myths

While taking a nutrition class this year I was relieved to learn that most of the currently popular diets and ‘theories’  really have no proven advantages, and so we can safely direct our attention to simply eating tasty, balanced meals.
One theme kept coming up again and again among diverse topics like macronutrients, vitamins & mineral supplementation, weight management, etc.:  the best route to healthful eating is to really choose what you eat from your own common sense rather than letting that choice be made for you by fad-diets or pseudo-scientific nutrition theories, marketers, or being too busy to think about what you’re eating. 

Food restriction
Some diets recommend tight adherence to healthy food at every meal, while others say that you can throw all caution to the wind after 6pm or Friday through Sunday. Either extreme is likely to be counterproductive. Being always restrictive with food choices or eating times is not really sustainable in the long run, and even if you do stick it out for a while, caloric deprivation is likely to slow your metabolism, making it harder to stay in shape. Restricting part of the time while gorging on junk food or rich foods every evening or weekend as a “reward” will still keep you addicted to those foods, with the healthy options seeming like a kind of penance to be endured. But if you take the time to really discover foods that are both satisfying and good for you, and grow into a habit of eating those most of the time, then there’s no harm in having a big desert or appetizing snack or a meal out a couple of times a week. If you find yourself craving not-so healthy things too often, instead of feeling guilty about it or mindlessly following the impulse, make a mental or written list of the food with a promise to yourself to enjoy those foods in the near future time (for example, plan to eat whatever you feel like every Saturday).

Contrary to some popular fad diets, avoiding particular food groups (e.g. carbs or fats), or combinations of foods (e.g. avoiding having starchy foods and protein in the same meal), or cooked foods, does not bestow any physiological benefits to us humans. Those diets sometimes work in the short run for weight loss because in changing our eating habits to something unusual and restrictive we may temporarily consume fewer calories, but there is no evidence that the weight will stay off in the long run (unless you continue the restrictive regimen, which almost no one can). Our gastrointestinal tract and enzymes digest all foods simultaneously without inhibiting one another, and a meal provides the greatest nourishment and sense of satiety if carbohydrates, proteins, oils, and fiber are all present together. So unless your nutritionist recommends a dietary modification (e.g. due to diabetes or allergies), eating balanced whole-foods meals with lots of vegetables is your best bet for health and enjoyment.

Low-fat or zero-calorie
Reduced-fat does not mean low calorie or “good for you”[1]; extra sugar is often used to compensate when a commercial recipe is re-engineered to capitalize on the fat phobia of the 80’s & 90’s. Experiments show that we tend to eat more of something if we think it is low fat, often resulting in more total calories consumed. In the US today, people eat less fat than previous generations, and yet many more are overweight. The current scientific consensus is that fat in moderation (several tablespoons daily of healthy fats from nuts and oils like olive, canola or coconut) is good for us; in fact it’s necessary for our body functions, vitamin absorption, and longer-lasting satiety. In replacing foods high in saturated animal fats, it’s important to replace them with good (unsaturated) fats, not refined carbohydrates. The recent studies showed that replacing a diet high in refined carbs with one rich in polyunsaturated fat lowers blood pressure, improves lipid levels, and reduces risk of cardiovascular disease[2] and type-2 diabetes[3].

Over the past century Western diets have become deficient in alpha-linolenic omega-3 fatty acids, which are important for minimizing heart disease risk, inflammation, blood pressure and weight gain. One tablespoon of ground flax seed[4] contains the recommended 2 g of omega-3 (ALA form), as do two tablespoons of canola oil or ¼ cup walnuts. To get even more omega-3s (in the more potent DHA form), we can eat wild-caught coldwater fish like salmon, trout or sardines once a week or more, or use vegan algae-based supplements. The only fats worth avoiding entirely are trans-fats in processed foods (check the ingredient list for any partially hydrogenated oils).

Light or zero-calorie does not necessarily mean good for weight management either – these foods usually use non-nutritive sweeteners which are actually associated with greater weight gain[5]. One explanation is that regular consumption of sweet drinks and treats condition us to crave that level of sweetness, and so when assuaging our conscience with diet soda or intensely sweet sugar-free cookies we erode our ability to enjoy the subtler sweetness of fruits, vegetables, whole foods or other beverages, on net consuming more calories from other sources. Another hypothesis is that the zero-calorie sweeteners may play tricks on your satiety hormones as well as your palate – our craving for energy and dopamine release associated with consuming real sugars is not satisfied by zero-calorie sweeteners and we keep snacking to try to quell the dissatisfaction; in addition these sweeteners may thwart our body’s ability to sense how much is enough when eating real food[6].

Breakfast instead of a fast
Mornings are a busy time and many of us get in the habit of having only coffee or a bite of something sugary (serial, toast, etc.), devoid of lasting satiety. Others learn to skip breakfast altogether believing that it’s good for weight management or ‘detox’ or holding a mistaken belief that we should only eat when ravenous. But studies have shown that eating a substantial, nutrient and protein-rich breakfast within 1 hour of waking (up to 2 hours if you exercise in the mornings) is associated with significantly lower levels of stress, over-eating later in the day or weight problems. So a breakfast of protein, healthy fats and unrefined carbs is one of the best things you can do for yourself; besides giving your energy it improves mood by counteracting the effects cortisol (a stress hormone that’s triggered by being woken up, especially if sleep deprived, low blood glucose, etc.).

There’s also nothing heroic or healthy in going to bed hungry; if you get hungry in the evenings after dinner, having a light but filling snack will make you sleep much better which will in turn make you less stressed and hungry the next day.

Exercise Fuel
It’s good to wait at least 3 hours after a large meal before a workout, but don’t wait so long that you begin feeling seriously hungry. Exercising when hungry usually means your mood and performance will be worse during the workout and you will end up burning fewer calories and building less muscle.

[2] Appel L, Sacks F, Carey V, et al. Effects of protein, monounsaturated fat, and carbohydrate intake on blood pressure and serum lipids: results of the OmniHeart randomized trial. JAMA. 2005;294:2455-64
[3] Riserus U, Willett WC, Hu FB. Dietary fats and prevention of type 2 diabetes. Prog Lipid Res. 2009;48:44-51.
[5] S.P. Fowler, et al. Fueling the obesity epidemic? Artificially sweetened beverage use and long-term weight gain. Obesity, Vol. 16, June 5, 2008 (online), p. 1894. doi:10.1038/oby.2008.284.
[6] S.E. Swithers, A.A. Martin, and T.L. Davidson. High-intensity sweeteners and energy balance. Physiology & Behavior. Vol. 100, April 26, 2010, p. 55. doi: 10.1016/j.physbeh.2009.12.021.


Post a Comment


get my free ebook

get my free ebook
(click on image)

Follow by Email

About this blog

The goal of this blog is to celebrate delicious food that's also practical. Contrary to certain foodie trends, we believe there is no reason for amazing food to be expensive or complicated or time consuming.

Our hope is to bridge the ethos of the slow and simplicity movements (cooking delectable traditional foods from scratch, connecting with others, minimizing waste and clutter) with the everyday needs and constraints of “the 99%”.

Check out the recipe section for easy, healthy, authentic recipes from the world’s vegetarian traditions that ANYONE can make.