Towards a comprehensive theory of obesity and a healthy diet: The causal role of oxidative stress in food addiction and obesity

Background: Obesity is a major public health problem whose prevalence has been rapidly increasing in the United States (U.S), and globally. It is one of the leading causes of preventable deaths globally and contributes to the development of many diseases. Methods: The search was limited to studies published in English and other languages involving both animal and human subjects. Articles selected included preclinical studies, randomized clinical trials RCTs, observational studies, meta-analyses, narrative and systemic reviews providing primary quantitative data with a measure of obesity or food addiction as an outcome. Over 5000 articles were found in the first round of search which was filtered to 506 articles. Results: Oxidative stress plays a critical role in food addiction and is both a cause and mediator of obesity. Reactive oxygen species play a direct role in adipogenesis and oxidative stress modulates all factors involved in obesity including genetics, sleep, gut microbiome, insulin, ghrelin, inflammation, adipokines, leptin, stress, HPA axis, and the hypothalamus. Conclusions: The idea of thinking of combating obesity from the lens of calorie count, low carbohydrate, high or low-fat, vegetarian, vegan, plant-based, or animal-based diet is fundamentally wrong. The best way to look at obesity is through the framework of systemic redox homeostasis. Since redox homeostasis is tilted towards increased reactive oxygen species production, and excessive antioxidant intake can result in oxidative stress, an antioxidant and prooxidant food ratio of 2:3 per meal is the ideal nutritional ratio for good health and ideal weight. A ratio of 3:4 is ideal for obese individuals because of their state of chronic oxidative stress and inflammation. Physical activity, sleep quality, psychological stress, maternal prenatal diet and oxidative stress promoting disease conditions are important modulators of oxidative stress and obesity.