The science of nutrition is changing and not in the way you might expect. After years of "reductionist" thinking - where food has been viewed as the sum of its parts - a call to treat food as food has been sounded. No more poring over nutrition labels to calculate grams of fat or chasing down the latest go-to chemical - be it vitamin E, fish oil or omega-3. Instead we are being asked to call a potato a potato and a piece of steak... well... a piece of steak.
If you haven't heard about this sea change yet, you are not alone. The food science industry that markets "food products" for our consumption has done a good job giving their laboratory creations a semblance of health with phrases like "low fat" and "high in vitamin C". For our part, the medical community is also to blame. Despite evidence to the contrary, we have been slow to renounce the "fat is bad" mantra or break away from the nutrient-based approach to eating that first swept the country over 30 years ago.
Until very recently, the dissenting opinion was expressed mainly by food journalists and self-proclaimed naturalists. In the book Good Calories, Bad Calories, Gary Taubes argues persuasively that the science behind vilifying fats is fatally flawed and proposes that carbohydrates, and in particular sugar and high fructose corn syrup, are the real bad guys. Michael Pollan, perhaps the best quoted food journalist-cum-activist, goes further to suggest the whole notion of understanding food by its constituent parts - fat, protein and carbohydrates or even saturated fats, unsaturated fats, and trans fats - is plain wrong. He opens In Defense of Food with three dictums for healthful eating: "Eat food. Not too much. Mostly plants."
Now the scientific and medical literature is coming around. A review in the Archives of Internal Medicine of over 500 trials found "insufficient evidence" that the intake of dietary fat (except for trans fat) is associated with coronary heart disease.1 More recently, an editorial published in the Journal of the American Medical Association (JAMA) August 2010 entitled "Dietary Guidelines in the 21st Century - a Time for Food" writes "little of the information found on food labels' ‘nutrition facts' panels provides useful guidance for selecting healthier foods to prevent chronic disease."2
Don't let the plain academic language lull you - what these scientists have published in arguably the world's most prestigious medical journal is that the entire approach to food based on nutrients is wrong.
It's not that eating the right nutrients is hard (how are you supposed to know if less than 30% of your calories comes from saturated fats?) and that the science of nutrient-based eating is bad (this is too academic to get worked up about), it's that our focus on nutrients has actually made our food more unhealthy. In an effort to engineer "better" foods, we created trans fats, which we now know are deleterious to health, and food products that are low in fat but high in dough conditioners (whatever that is). Indeed, as saturated fat consumption has decreased, our collective burden of chronic disease and obesity has only increased.
So if fat is not bad, and we shouldn't be thinking about food in terms of individual nutrients, what are we left with? Surprisingly, we are pretty much where we were in our grandparents' generation, a time before we thought we could improve health by manipulating individual nutrients, and when food was just food. As the JAMA article concludes "... although this approach may seem radical, it actually represents a return to more tradition, time-tested ways of eating."
In fact, the most convincing studies of dietary patterns that prevent or retard chronic disease are food-based. Fruits, vegetables, whole grains, and nuts have been consistently associated with lower risk of disease while fish consumption has lowered the risk of death from heart disease. And these effects are above and beyond what you see from diets with equal levels of protein, fat, and carbohydrates.*
A food-based approach to eating is not only healthier but also easier. Instead of worrying about things you can't see, smell or taste; it asks you to pay attention to what you are putting in your mouth. It supports an eating plan of fruits and vegetables, whole grains, and unfettered meats over processed foods, packaged meats, and sugar-laden beverages; and favors home-cooked food over store-brought or restaurant meals.
So the next time the hunger pangs strike, check your energy bar at the door and drive on by the local diner. Instead go to your local grocery store, buy yourself some fresh food, and prepare yourself a hearty, wholesome and healthy meal.
Copyright Shantanu Nundy, M.D.
*It's not hard to imagine why. Fish has way more in it than protein, different types of fat, and carbohydrates; and even if we could categorize every vitamin and micronutrient in fish we wouldn't yet understand how these nutrients work synergistically to impact health.
1 Mente A, de Koning L, Shannon HS, Anand SS. A systematic review of the evidence supporting a causal link between dietary factors and coronary heart disease. Arch Intern Med. 2009 Apr 13;169(7):659-69.
2 Mozaffarian D, Ludwig DS. Dietary guidelines in the 21st century-a time for food. JAMA. 2010 Aug 11;304(6):681-2.