Is it possible to lose weight without counting calories or shrinking portion sizes? A new analysis of a clinical trial suggests that changing the type of food eaten and lowering its "caloric density" may help achieve just that.
اضافة اعلان
According to the analysis, published in the journal JAMA Network Open, the trial included 244 overweight adults, randomly divided into two groups of 122 participants each.
The first group followed a low-fat plant-based diet for 16 weeks, based mainly on vegetables, fruits, grains, and legumes, while the control group continued their usual diet.
Participants in neither group were asked to count calories or stick to a specific calorie ceiling. The final analysis included data from 223 people who completed the trial.
491 Fewer Calories a Day
Results showed that the total weight of food participants ate did not change significantly. In the plant-based group, the average amount of food rose from about 1,825 grams to 1,931 grams per day, but this change was not statistically significant.
By contrast, average energy intake within that same group dropped from 1,834 to 1,343 calories per day, a reduction of about 491 calories.
The control group also saw a decline, of about 134 calories per day, meaning the difference between the two groups was about 357 calories in favor of the plant-based diet.
Over the 16 weeks, the plant-based group lost an average of about 6.4 kilograms, compared to half a kilogram in the control group, a net difference in weight loss of 5.9 kilograms between the two groups.
The Secret Lies in "Caloric Density"
Researchers attribute the results to the roughly 30 percent lower caloric density of the plant-based group's food. Caloric density refers to the number of calories contained in each gram of food.
Foods rich in water and fiber, such as vegetables, fruits, and legumes, provide greater volume and weight for fewer calories, which may help people feel full without reducing the amount of food they eat.
The researchers found that lower caloric density was associated with greater weight loss, even after accounting for changes in calorie intake.
Not All Plant-Based Food Is Low-Calorie
The findings don't mean that simply switching to a plant-based diet guarantees weight loss, since some plant-based foods have high caloric density, including oils, nuts, seeds, and avocados, as well as certain plant-based sweets and processed products.
The results are subject to important limitations, most notably that food intake was measured using self-reported logs kept by participants, and the trial was limited to volunteers who may not represent the general population. The follow-up period also lasted only 16 weeks, so the results don't show whether the weight loss would be sustained over the long term.
The study was funded by the Physicians Committee for Responsible Medicine, an organization that advocates for plant-based nutrition, but the researchers noted that the funder did not influence the study's design, data analysis, or the decision to publish it.
Overall, the findings suggest that weight loss may not be tied to the amount of food alone, but also to the number of calories contained in each gram of it.
