Eschewing Bananas Is Not the Cure to America's Health Woes

Low-carb diets are effective when they reduce your overall calorie intake. But loyalty to a diet for its own sake defeats the point.

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In a recent post, I suggested that diets recommending a combination of low carbs and high saturated fat may offer less benefit -- and more risk -- than low-carbohydrate diet gurus would have us believe. According to a 25-year Swedish study, an increase in dietary fat intake coincided with an increase in serum cholesterol, especially with an increased intake of saturated fat.

As predicted, a tsunami of responses followed, many of them angry. Among the more common complaints was my apparent misrepresentation of the low-carbohydrate regimen as, for example, a breakfast consisting of a "greasy pile of bacon, sausage and eggs." In my defense, at least one notable low-carb proponent -- also mentioned admiringly by many readers of the post -- has claimed publicly that he has just such a breakfast every morning, followed by a lunch of "a couple of cheeseburgers or a roast chicken" and dinner of "at least a pound of rib eye or New York steak."

Apparently, this fellow is an outlier. No, the commenters insist, a low-carbohydrate diet is not rich in greasy pork products, but "in lean meats, fish, veggies, and berries." Which is to say, rich in high-nutrient, low-calorie foods.

Well, I stand corrected. A diet rich in lean meats, fish, veggies and berries sounds like a very sensible diet indeed. Who among us would argue with that? Such a diet is also likely to be low in ice cream, soda, beer, chips, fries, Bloomin' Onions, cake, candy, and Whoopee pies. Which is to say, low in calories.

But is a low-carbohydrate diet by definition lower in calories than a carb-rich diet? Not necessarily, particularly if one consumes a daily regimen of bacon, cheese and eggs followed by an entire chicken and topped off with "at least" a pound of well-marbled steak. But most of us would not and do not eat like this.

For most people, strictly limiting one food group in their diet -- be it carbohydrates or fat -- also reduces the number of calories in that diet. The reason for this is pretty obvious. While low-carbohydrate diets allow hamburgers and steak, they do not allow buns or fries or even ketchup. They allow butter but not the bread to slather it on, cream cheese but not the bagel, heavy cream but not ice cream. They forbid all pastries, all breaded fried foods, all sweetened dairy products. You get the picture. So for most real people living in the real world, a low-carbohydrate diet is a low-calorie diet. And as we all know, any diet truly low in calories will help us lose weight -- which, if maintained over time, lowers our risk of heart disease and diabetes. But the key here is "maintained over time."

Yes, of course, some people find a low-carbohydrate diet easier to tolerate than a low-fat diet, and are more likely to stick with it. Others find that a low-carbohydrate diet makes them feel better, lowers their "bad" cholesterol levels, and improves their health overall. This is particularly true for people who find it easier to simply cut out carbohydrates than to moderate them -- that is, people who can't resist overeating carbohydrates, especially sweets. Cutting back on sweets and simple carbohydrates is probably a good idea for most of us, and no one is saying that pasta is the perfect food. But Americans already consume more meat and saturated fat than do most other citizens of the planet, and it doesn't seem to be doing us much good.

As we all know -- and as I've already stated -- any diet that reduces calorie intake will result in weight loss. The tricky part is keeping that weight off. The National Weight Loss Registry -- has for decades tracked people who have lost significant amounts of weight and kept it off. The most potent predictor of permanent weight loss in this group? A relatively low-fat diet rich in vegetables and whole grains. Regular exercise -- about an hour of walking a day -- also seems to contribute.

Does that mean that we should substitute carbohydrates for fat, calorie for calorie, or drastically reduce our fat intake, or consume pounds of sugar-filled low-fat products? Absolutely not. But it does give evidence that for the majority of humans, a balanced diet low in sugar and saturated fat and high in fruit, vegetables, nuts, and whole grains and moderate amounts of lean protein is -- when combined with regular exercise -- the best prescription for health.