Carbohydrate as a nutrient in adults: range of acceptable intakes

Abstract

This review considers the acute and chronic effects of different levels of carbohydrate (CHO) intakes. The type of CHO consumed, especially glucose vs fructose, affects the glycaemic, insulinaemic and thermogenic responses. In addition, other aspects of food (type of starch, method of processing or cooking, presence of other nutrients) affects the glycaemic response (glycaemic index). In general, the greatest bene®t to health is derived from consuming foods with a low glycaemic index and a high non-starch polysaccharide (®bre) content. Healthy, moderately active adults require at least 200 g CHO per day to sustain normal brain metabolism and muscle function. Moreover, the CHO content should represent at least 50% of energy intake. Higher intakes of CHO can have deleterious effects on blood lipids (especially plasma triacylglycerol) in middle-aged and elderly subjects, and are really only appropriate for subjects with a high level of physical activity who need to maintain muscle glycogen content. Meals with a high carbohydrate content can lead to problems of postprandial hypotension in the elderly, and impaired exercise capacity in patients with angina.

Modifiable Lifestyle Factors and the Metabolic Syndrome in Older Men: Effects of Lifestyle Changes

“…Because low‐fat, high‐carbohydrate diets have traditionally been recommended to reduce CVD and diabetes mellitus risk, 23 the influence of fat and carbohydrate on the metabolic syndrome was further examined. The men were stratified into three groups: low carbohydrate, high fat (n=742); low fat, high carbohydrate (n=734); and those falling into neither category, who were designated low carbohydrate, low fat (n=1,457).…”

Slc2a5 (Glut5) Is Essential for the Absorption of Fructose in the Intestine and Generation of Fructose-induced Hypertension

“…Fructose is a monosaccharide and is one of the three most important blood sugars along with glucose and galactose (1)(2)(3). It plays an essential role in vital metabolic functions in the body, including glycolysis and gluconeogenesis (4 -6).…”

“…The classic model of sugar absorption indicates that sodium glucose cotransporter 1 (Sglt1) 3 and Glut5 absorb glucose and fructose, respectively, from intestinal lumen to cytosol, and Glut2 transports both glucose and fructose from the cytosol to the blood (9 -19). Glut2 has high affinity for glucose and a moderate affinity for fructose, whereas Glut5 predominantly transports fructose with very low affinity for glucose (9 -19; reviews in Refs.…”

Clinical insights into the lifestyle and dietary management of insulin resistance syndrome

“…24,25 A moderate carbohydrate intake of 40 -45% of total energy intake is recommended, and is achieved by replacing some of the carbohydrate in the diet with unsaturated fat. 8,11,26 Protein When protein is consumed it increases the postprandial insulin response yet decreases the postprandial glucose response. Apart from the saturated fat content of protein foods, the type of protein itself can have an impact on insulin action.…”