Beyond the Calories—Is the Problem in the Processing?

Janese Laster, Leigh A. Frame

The purpose of this review is to describe the trends in dietary patterns and food quality over time along with the possible role of ultra-processed foods in obesity, chronic diseases, and all-cause mortality in the US population. There is a rising obesity epidemic, corresponding chronic diseases, and increases in ultra-processed food consumption. 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 found ultra-processed foods as a contributor to decreased satiety, increased meal eating rates, worsening biochemical markers, and more weight gain. In contrast, Blue Zone, indigenous South American, and Mediterranean populations with low meat intake, high fiber, and minimally processed foods have far less chronic diseases, obesity rates, and live longer disease-free. As the USA continues to industrialize, food has become more processed and cheaper and more convenient along with the coexistent rise in obesity prevalence. This review highlights the overall trends in food: mild improvements in dietary quality in higher socioeconomic populations, but no significant increases in whole fruit, vegetables, legumes, or nuts. Consumption of ultra-processed food is associated with weight gain and may contribute to metabolic syndrome and chronic disease. To combat this epidemic, we must create and disseminate detailed recommendations to improve diet quality and overall nutrition.