Research Offers Insights on Processed Foods
Processed foods in the form of fast foods and packaged meals have been taking flak from all quarters as buzz words like organic, natural, local, clean eating and whole foods have become part of the language.
There have been few peer-reviewed studies to investigate the effects of unhealthy foods but new research from the National Institute of Health published in the British Medical Journal offers scientific evidence supporting the unprocessed food movement.
The findings are from two studies and the major implications are that less processed foods in the diet translated to better heart health and longevity while ultra-processed items caused more weight gain.
Effects of Unhealthy Foods Include Weight Gain
The NIH paper published in August recruited 20 young and healthy adults who were placed in a controlled environment for 28 days. The methodology involved feeding the participants on a diet of fast foods and packaged meals for 14 days and then switching to an unprocessed menu for the next 14 days while observing their health markers.
The study was particularly employed randomized controlled trial (RCT) techniques, considered to be the holy grail by researchers as they aim to determine cause and effects links. Studies with RCT methodology are few as they are terribly expensive to conduct and they ran for far shorter periods than a month.
The results were striking as participants gained an average of around 500 calories more than their counterparts on an unprocessed diet. As a result, those on ultra-processed gained an average of two pounds over 14 days. They then lost the two pounds after reverting to an unprocessed menu for the next 14 days.
The weight gained persisted even after researchers made elaborate attempts to ensure meals between the diets were made as similar as possible. The two diets consisted of similar composition of carbohydrates, proteins, fats, fiber, nutrients and sodium with soluble fiber being added to drinks in the processed foods diet.
Theories on Ultra-processed Foods
The study raised the question of why there was such a marked difference in calorie intake even though the foods were more or less the same in the two diets. The researcher came up with several theories to explain the phenomenon. The first clue was in the composition of fast foods and packaged meals as since they are softer and easier to eat, participants consumed more before the body signaled fullness.
It is accepted that the brain releases hormones controlling satiety are released around 15 minutes after we begin eating. The composition of ultra-processed foods means individuals can race ahead of this natural mechanism when eating and consume extra calories before the body can do anything. Observations in the NIH study supported these assertions as appetite-reducing and hunger-inducing hormones test results were consistent with the theory.
Ultra-processed foods are also packed with calories, a trait known as energy density. When food is more energy-dense it can contain h more calorie content in relatively small volumes.
Researchers recognized the convenience and affordability of processed foods and encouraged gradually replacing ultra-processed items with healthier alternatives.