A new study by the American National Institutes of Health (NIH) has found a clear causal link between the consumption of highly processed foods and weight gain. The study, published in the journal Cell Metabolism, shows that people who consume exclusively processed foods gain around one kilogram in just two weeks, compared to those who prefer unprocessed foods. The researchers, led by Kevin Hall, developed a new method of investigation for the study, which involved dividing 20 participants into two groups and serving one group a menu of processed foods for two weeks, while the other group was served unprocessed foods.
Despite the fact that both menus had identical ingredients, the group that consumed processed foods consumed an average of 508 more calories per day than the control group, leading to an average weight gain of one kilogram after two weeks. When the menus were switched, the group that had previously consumed unprocessed foods gained weight after switching to processed foods, while the group that had previously consumed processed foods lost weight after switching to unprocessed foods. The study is the first to establish a causal link between processed foods and weight gain.
The researchers suggest that the reason for the increased calorie consumption may be due to the fact that people eat processed foods more quickly, before their brains have registered that they are full. Further studies with more participants and over longer periods of time are needed to investigate this theory. The researchers also caution that their results may not be entirely applicable to everyday life, as factors such as preparation time and cost were not taken into account during the study.
