Ultraprocessed Foods and Obesity Risk: A Critical Review of Reported Mechanisms

Resumen

Epidemiologic evidence supports a positive association between ultraprocessed food (UPF) consumption and body mass index. This has ledto recommendations to avoid UPFs despite very limited evidence establishing causality. Many mechanisms have been proposed, and thisreview critically aimed to evaluate selected possibilities for specificity, clarity, and consistency related to food choice (i.e., low cost, shelflife,food packaging, hyperpalatability, and stimulation of hunger/suppression of fullness); food composition (i.e., macronutrients, foodtexture, added sugar, fat and salt, energy density, low-calorie sweeteners, and additives); and digestive processes (i.e., oral processing/eatingrate, gastric emptying time, gastrointestinal transit time, and microbiome). For some purported mechanisms (e.g., fiber content, texture,gastric emptying, and intestinal transit time), data directly contrasting the effects of UPF and non-UPF intake on the indices of appetite, foodintake, and adiposity are available and do not support a unique contribution of UPFs. In other instances, data are not available (e.g.,microbiome and food additives) or are insufficient (e.g., packaging, food cost, shelf-life, macronutrient intake, and appetite stimulation) tojudge the benefits versus the risks of UPF avoidance. There are yet other evoked mechanisms in which the preponderance of evidenceindicates ingredients in UPFs actually moderate body weight (e.g., low-calorie sweetener use for weight management; beverage consumptionas it dilutes energy density; and higher fat content because it reduces glycemic responses). Because avoidance of UPFs holdspotential adverse effects (e.g., reduced diet quality, increased risk of food poisoning, and food wastage), it is imprudent to make recommendationsregarding their role in diets before causality and plausible mechanisms have been verified.