Physiological responses to carbohydrate overfeeding

Abstract

Purpose of review To consider emerging research into the physiological effects of excessive dietary carbohydrate intake, with a particular focus on interactions with physical activity. Recent findings A single episode of massive carbohydrate overload initiates physiological responses to stimulate additional peptide hormone secretion by the gut and the conversion of carbohydrate into lipid by the intestine, liver and adipose tissue. These acute responses maintain glycaemic control both via increased oxidation of carbohydrate (rather than lipid) and via nonoxidative disposal of surplus carbohydrate into endogenous glycogen and lipid storage depots. Sustained carbohydrate overfeeding therefore results in a chronic accumulation of lipid in the liver, skeletal muscle and adipose tissue, which can impair insulin sensitivity and cardiometabolic health in general. Beyond any direct effect of such lipid deposition on body mass/composition, there is not yet clear evidence of physiologically meaningful metabolic or behavioural adaptations to carbohydrate overfeeding in terms of other components of energy balance. However, regular physical exercise can mitigate the negative health effects of carbohydrate overfeeding, independent of any effect on the net carbohydrate surplus. Summary Research in this area has advanced understanding regarding the mechanisms of weight gain and associated health outcomes within the modern context of an abundant supply of dietary carbohydrate.

Ultra-Processed Food Intake Is Associated with Non-Alcoholic Fatty Liver Disease in Adults: A Systematic Review and Meta-Analysis

“…Combined with high fat is excessive intake of carbohydrates, such as fructose, which promote hepatic de novo lipogenesis. Chronic, recurrent episodes of lipogenesis increase IHTG deposition [ 46 , 47 , 48 ]. Low-quality carbohydrates, such as those found in UPFs, are typically lower in fibre.…”

“…Combined with high fat is excessive intake of carbohydrates, such as fructose, which promote hepatic de novo lipogenesis. Chronic, recurrent episodes of lipogenesis increase IHTG deposition [46][47][48]. Low-quality carbohydrates, such as those found in Macronutrient composition: The macronutrient profile of UPFs is characterised by high total fat, saturated fat and free sugars from refined carbohydrates, as well as low fibre [45].…”

Resveratrol and (-)-Epigallocatechin-3-gallate Regulate Lipid Metabolism by Activating the AMPK Pathway in Hepatocytes

“…Fat and cholesterol are important components of lipids [ 2 ]. When people and animals suffer from excess nutrition or stress, the excess energy in the body will be converted into fat and deposited in the liver, resulting in the occurrence of fatty liver syndrome, which will adversely affect the health of people and animals [ 3 , 4 ]. In addition, the liver is the main organ responsible for cholesterol synthesis [ 5 ].…”

Editorial: Is reducing dietary carbohydrate the way to go?

“…In the final contribution to this issue, Walhin et al [15] discuss the adverse health consequences of carbohydrate overconsumption. The human body has limited carbohydrate storage capacity.…”

“…The conversion of carbohydrates to lipids occurs predominantly in the liver [16] and can cause fatty liver disease when high carbohydrate intake is combined with excess energy intake – a metabolic response that is not seen with excess high fat intake. Wahlin et al [15] review strategies, like exercise or dietary supplementation with omega-3 fatty acids that can counteract the adverse health effect of high carbohydrate intake and the mechanisms responsible for these effects.…”