Food during the night is a factor leading to obesity

Abstract

The present review aims to present evidence obtained in clinical surveys and experimental studies that point out the relevance of meal schedules on metabolism and body weight. Recent findings indicate that in spite of ingesting equivalent amounts, food ingestion during the day or during the night can have completely different effects on metabolism determining bodyweight gain and propensity to obesity. Such findings find support in studies of the circadian rhythms, driven by a biological clock located in the anterior hypothalamus, which transmits temporal signals to the body including functions for energy balance. Circadian cycles are normally driven by the alternation of the day-night luminosity cycles, however metabolic changes resulting from food have proven to be powerful temporal signals capable of modifying de temporal order in tissues and cells. Considering the power of food elicited signals, the feeding schedule must coincide with the timing signals driven by the biological clock. Thus eating during the hours normally assigned for sleep and rest leads to a loss of coordination between metabolic rhythms and the biological clock. This circadian disruption occurs at different levels, among cells in a specific tissue as well as in the molecular processes in cells. The aim of this review is to emphasize the adverse effects that meals during the night can exhert on metabolism, we provide evidence about circadian and metabolic alterations at different regulatory levels.

Gut Microbiota and Obesity: Prebiotic and Probiotic Effects

“…Obesity is a medical condition of multifactorial causes, ranging from the influence of the nearby environment on the acquisition of predisposing habits, such as the consumption of foods high in refined carbohydrates and saturated fats and a sedentary lifestyle. Genetic predispositions are also among the principle causes [5]. On the other hand, socioeconomic development, transport, urban planning, environmental, agricultural, educational, processing, distribution and marketing policies on food influence dietary habits and preferences, as well as people's level of physical activity [5,6].…”

“…Genetic predispositions are also among the principle causes [5]. On the other hand, socioeconomic development, transport, urban planning, environmental, agricultural, educational, processing, distribution and marketing policies on food influence dietary habits and preferences, as well as people's level of physical activity [5,6].…”

“…It is proposed that eating at times when the body is prepared for rest increases body weight. At rest there are low levels of hormonal activity, a low body temperature and low activity of nutrient absorption which alters energy homeostasis and facilitates the accumulation of energy, increasing body weight [5,8].…”

“…As already described, the gut microbiota is made up of a diversity of pathogens which highlights the presence of Gram-negative or Gram-positive bacteria. The equilibrium of this ecosystem provides us great health benefits, in the absorption and digestion of nutrients, as well as influencing immune function [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18].…”

“…A hypothesis of the positive influence of microbiota on fat storage exists, and several studies carried out in mice have proven the role of certain fatty acids in the diet in the prevention of obesity, an effect mediated through changes in the composition of gut microbiota. Studies in humans have also shown a relationship between a decrease in Bacteroidetes in obese individuals and a greater proportion of these in the faecal microbiota in subjects who have undergone hypocaloric diets and who have managed to reduce their weight [5,7].…”