Ask the Doctors by Eve Glazier, M.D. and Elizabeth Ko, M.D

Study's Participants Lost Weight Without Counting Calories

Dear Doctor: Is it true that just cutting back on refined sugar, refined grains and highly processed foods can lead to weight loss without cutting calories? If so, count me in. But I could eat a whole lot of whole grains and vegetables before being satisfied. That's still a lot of calories.

Dear Reader: Based on the specifics, we think you're referring to the results of a clinical trial published earlier this year in the Journal of the American Medical Association. The takeaway from the research itself is extremely interesting, but equally fascinating has been how the results have been interpreted in the media. Much of the coverage trumpeted the idea that (at last!) here's a diet where you lose weight without counting calories. And though it's true that caloric restrictions were not built into the study, among the findings was that participants wound up consuming an average of about 500 fewer calories per day.

A team of researchers working in partnership with the National Institutes of Health studied 600 overweight people over the course of a year as they followed eating programs consisting of only high-quality whole foods and beverages. That means heavy on fruits, vegetables, lean proteins, healthful fats, and whole grains and legumes, and few or no highly processed foods. Not only are those loaded with salt, fat, sugars and highly refined carbohydrates, but they've been repeatedly linked to obesity, diabetes, cardiovascular disease and various cancers.

The actual point of the study was whether an individual's genetic makeup or insulin metabolism can predict weight loss or health outcomes. To that end, the study participants were randomly assigned to a diet that was either low in fat, or one that was low in carbs. Over the course of the year the people in the study, all of whom were overweight, also attended 22 counseling sessions with a dietitian.

Just so you know, the conclusion was that genotype and insulin production didn't appear to be predictors of weight loss in either group. Also, neither diet appeared to be superior for weight loss. But what got the most ink was that so many participants lost weight without counting calories. Low-carb participants lost an average of 13 pounds each, while the low-fat group lost an average of 11.7 pounds each. A few people dropped significant weight -- up to 60 pounds -- and some gained weight. And both groups saw drops in waistline measurements, body fat percentage, blood pressure, and fasting levels of insulin and glucose.

So what happened? It appears that by quitting junk foods in favor of a diet of high-quality whole foods, people in the study naturally ate fewer calories without trying to cut back. The fact that all of those health markers also moved in a positive direction speaks volumes for the benefits of this type of eating. What strikes us is that, for all the diets and eating plans and food hacks that have emerged over the decades (centuries, really), it always comes back to the basics -- a balanced diet of whole foods, lean meats, good oils, and plenty of fresh fruit and vegetables.

Now, please, go eat an apple.

(Send your questions to, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)