Gaining Weight? Ultra-Processed Foods May Be to Blame

Gaining WeightSusan Brown Health and Wellness Editor

Let’s assume you’ve been watching your caloric intake and have ramped up physical activity with the ultimate goal of improving health markers through weight loss. Yet, the numbers on the scale continue to disappoint, as you maintain, or even gain weight. What gives? Contemporary diet plans, whether keto, paleo, low carb, low fat, high protein, plant-based or vegan, all share a common thread: get back to basics by consuming whole foods and avoiding processed foods. Ultra-processed foods, described as “cheap industrial sources of dietary energy and additives formulated through a series of ‘processes’ and containing minimal whole foods,” are the most likely culprits of weight gain leading to obesity. In fact, 60 percent of the standard American diet consists of ultra-processed foods, while the nation’s obesity rate is quickly approaching 40 percent.

Ultra-processed food tends to be formulated from industrial ingredients, which blend starches, sugars and hydrogenated fats with additives, including preservatives, binders, artificial colors and flavorings, sweeteners and sensory enhancers. If that doesn’t scare you, perhaps the idea that food is “formulated”, or engineered to have enhanced appetite properties, should. Low cost, wide availability, long shelf life and the convenience of ready-to-eat foods come at a price to overall health and wellbeing. Consumption of ultra-processed foods is associated with adverse health outcomes in addition to obesity, such as high blood pressure, cancer and diabetes type 2, as well as a shortened life span.

Results of a one-month, in-patient, randomized and highly controlled trial recently published in the journal, Cell Metabolism, found that those exposed to a diet comprising ultra-processed foods unknowingly and regularly consumed an average of 500 extra calories daily, as compared to those given a diet of unprocessed whole foods. Although the diets were matched for calories, sugar, fat, fiber, sugar and macronutrients, study participants who were permitted to eat as much as they wanted, ate more when served ultra-processed foods despite rating them less tasty than the unprocessed ones. Consequently, those on the ultra-processed diet gained an average of two pounds, while people lost an equal amount of weight on the unprocessed diet. Ultra-processed foods may facilitate overeating and consequently obesity, as they are usually high in calories, laden with sugar, fat, and salt, making them not only palatable, but highly desirable as well.

NOVA, an alternative diet classification system developed by an international panel of researchers and food scientists, considers nature, extent and purpose of processing when categorizing foods and beverages into four groups:

  • Unprocessed or minimally processed foods include vegetables, whole grains, fruits, nuts, meats, seafood, poultry, eggs and milk.
  • Processed culinary ingredients include spices, herbs, garlic, healthy oils, and vinegars, all ingredients added in small amounts to create tasty meals at home.
  • Processed foods include convenience foods such as cheese, tofu, canned beans, oatmeal, tuna, nut butters or any foods that have been cleaned, cut, heated, canned or frozen.
  • Ultra-processed foods include sweetened breakfast cereals, white bread, packaged soups, hot dogs, candy, soft drinks, chips and ready-to-heat and eat meals.

While no causal relationship between ultra-processed food and human obesity has been definitively established, the study concluded that body fat mass increased on the ultra-processed diet and decreased on the unprocessed diet. This suggests that limiting consumption of ultra-processed food in favor of whole unprocessed foods may be an effective strategy for obesity prevention and treatment, as well as healthy weight maintenance for those within the normal BMI weight range. Ideally, for better health, weight maintenance and longevity, unprocessed whole food should make up the basis of everyone’s healthy diet plan.

Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake.
It’s Not Just Salt, Sugar, Fat: Study Finds Ultra-Processed Foods Drive Weight Gain.
Eating highly processed foods linked to weight gain.
Processed foods lead to weight gain, but it’s about more than calories.
Does eating ultraprocessed food affect weight gain? It’s complicated.
Heavily processed food like ready meals and ice cream linked to early death.
The vast majority of American adults are overweight or obese, and weight is a growing problem among US children.