Excerpted from the In Practice blog on boston.com.

Have you been following the latest in the ongoing controversy about whether a low-carb diet is healthier and better for weight loss than a diet low in fat?

If you lived in the 19th century you would have. The question of whether it matters what we eat — not only how much we eat — has been hotly contested for well over a hundred years.

A recent study reports that overweight and obese young people who lost weight on a reduced-calorie typical American diet and then ate a low-fat diet were at greater risk of regaining the weight because of slowed metabolism than those who consumed the same amount of calories via a low-carbohydrate diet. Those who ate more refined carbs were more likely to have insulin resistance and risk of diabetes.

The results imply that the calories in a “100 calorie pack” of cookies do not affect the body in the same way as, say, 100 calories of apples or fish or beans.

This new study, conducted at Children’s Hospital Boston and Brigham and Women’s Hospital, joins a long debate about the ideal composition of our diets.

In the 19th century, two nutritional gurus held diametrically opposed views.

William Banting, an English undertaker who lost weight by limiting bread, beer, and other starchy foods, espoused what we now call a low-carb diet.

The opposing point of view was held by New Jersey minister Sylvester Graham — yes, the inventor of Graham crackers — who encouraged a diet high in grains, fruits, and vegetables with little or, preferably, no meat. He heavily influenced Dr. John Harvey Kellogg (yes, that Kellogg), who ran a sanitarium in Battle Creek, Mich. Kellogg treated his patients with Graham’s high-carbohydrate regimen, including Kellogg’s Corn Flakes.

The new study reopens the debate, but by no means settles it in favor of the low-carb camp. The study was small (22 subjects) and the period in which the dieters were assessed for risk of regaining weight was short (four weeks).

So what do I tell my own patients about the low-carb vs. low-fat question?

It seems pretty clear that the rise in obesity in the United States has coincided with the rise in consumption of processed foods and more sedentary lifestyles.

I’m also impressed that my own patients’ experience mirrors the data from the National Weight Control Registry, which tracks people who have lost weight and maintained that weight loss: No one particular diet is magic.

Bottom line: Successful losers eat less, move more, and they eat fewer cookies than apples — which Banting and Kellogg would likely both have supported.