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.
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