Tip-toeing toward the truth

Last updated on April 10th, 2017

The big long-term weight gain study that the Harvard School of Public Health announced yesterday was officially published today in the New England Journal of Medicine (Changes in Diet and Lifestyle and Long-Term Weight Gain in Women and Men); it has gotten widespread press attention.  My first encounter with it was on ABC World News.  As I wrote last night, the ABC team, led by Dr. Richard Besser, focused on carbohydrates as the main factor in weight gain, labeling various forms of potatoes (chips, french fries, baked) as waistline enemy #1.  In this they were faithful to the Harvard press release.

The most encouraging aspect in the press release is the recognition that a calorie is not a calorie:

For diet, focusing only on total calories may not be the most useful way to consume fewer calories than one expends, say the researchers. Other yardsticks, such as content of total fat, energy density, or sugars, could also be misleading. Rather, they found that eating more healthful foods and beverages—focusing on overall dietary quality—was most important.

And what would those “more healthful foods” be? This is where it really gets good.  The press release continues:

• Focus on improving carbohydrate quality by eating less liquid sugars (e.g. soda) and other sweets, as well as fewer starches (e.g. potatoes) and refined grains (e.g. white bread, white rice, breakfast cereals low in fiber, other refined carbohydrates).
• Focus on eating more minimally processed foods (e.g. fruits, vegetables, whole grains, nuts, yogurt) and fewer highly processed foods (e.g. white breads, processed meats, sugary beverages).

I’d call that a good start toward a low-carbohydrate diet. Yes, it’s only a start. My way of “focusing on improving carbohydrate quality” is to eliminate most carbs from my diet, paring my carb consumption down to 40-45 net grams per day.  Almost none of my carbs come from grains.  I don’t believe everyone needs a low-carb diet like mine, but it’s an option to consider when just cutting down on pop and potato chips  fails to keep the pounds off.

The idea that there are qualitative differences in foods that make some more fattening than others, even when calorie counts are the same, is hardly new. This is the point that Gary Taubes made at some length in his 2007 book Good Calories, Bad Calories, and underscored again in his 2010 book Why We Get Fat.   Robert Atkins was making the point in 1972, and he wasn’t the first one to do so.  It used to be common knowledge that potatoes and sugary desserts were fattening.  Now the Harvard School of Public Health is tipping-toeing up to the notion as if it might turn and bite.

The healthy foods listed are an odd lot.  Are we really supposed to live on fruits, vegetables, whole grains, nuts and yogurt?  I am eating more fruits, veggies and nuts than I used to, but the main event is always eggs, cheese, meat, chicken or fish. I am skeptical of the procedures used to isolate the effects of individual foods.  If a subject ate extra helpings of potato chips and extra helpings of red meat, and gained weight, does that mean both foods are at fault?

At any rate, as I said yesterday, this is a step in the right direction.  I have to applaud when Frank Hu, the study’s senior author, says, “The idea that there are no ‘good’ or ‘bad’ foods is a myth that needs to be debunked.”