Processed foods highly correlated with obesity epidemic in the US

As food consumed in the U.S. becomes more and more processed, obesity may become more prevalent. Through reviewing overall trends in food, George Washington University (GW) researcher Leigh A. Frame, Ph.D., MHS, concluded that detailed recommendations to improve diet quality and overall nutrition are needed for consumers, who are prioritizing food that is cheaper and more convenient, but also highly processed. Her conclusions are published in a review article in Current Treatment Options in Gastroenterology.

"When comparing the U.S. diet to the diet of those who live in 'blue zones'—areas with populations living to age 100 without chronic disease—the differences are stark," said Frame, co-author of the article, program director for the Integrative Medicine Programs, executive director of the Office of Integrative Medicine and Health, and assistant professor of clinical research and leadership at the GW School of Medicine and Health Sciences. "Many of the food trends we reviewed are tied directly to a fast-paced U.S. lifestyle that contributes to the obesity epidemic we are now facing."

The rising obesity epidemic in the U.S., as well as related chronic diseases, are correlated with a rise in ultra-processed food consumption. The foods most associated with weight gain include potato chips, sugar sweetened beverages, sweets and desserts, refined grains, red meats, and processed meats, while lower weight gain or even weight loss is associated with whole grains, fruits, and vegetables. Other food trends outlined in the report include insufficient dietary fiber intake, a dramatic increase in food additives like emulsifiers and gums, and a higher prevalence of obesity, particularly in women.

In mice and in vitro trials, emulsifiers, found in processed foods, have been found to alter microbiome compositions, elevate fasting blood glucose, cause hyperphagia, increase weight gain and adiposity, and induce hepatic steatosis. Recent human trials have linked ultra-processed foods to decreased satiety (fullness), increased meal eating rates (speed), worsening biochemical markers, including inflammation and cholesterol, and more weight gain. In contrast, populations with low meat, high fiber, and minimally processed foods—the 'blue zones'—have far less chronic diseases, obesity rates, and live longer disease-free.

"Rather than solely treating the symptoms of obesity and related diseases with medication, we need to include efforts to use food as medicine," said Frame. "Chronic disease in later years is not predestined, but heavily influenced by lifestyle and diet. Decreasing obesity and chronic disease in the U.S. will require limiting processed foods and increasing intake of whole vegetables, legumes, nuts, fruits, and water. Health care providers must also emphasize lifestyle medicine, moving beyond 'a pill for an ill.'"