Journal Article

24-h severe energy restriction impairs postprandial glycaemic control in young, lean males

Funnell, Mark P., King, James A., Sargeant, Jack A., Hulston, Carl J., Stensel, David J., Biddle, Jack, Maher, Tyler, Clayton, David J., James, Lewis J.

2018

Overview

Intermittent energy restriction (IER) involves short periods of severe energy restriction interspersed with periods of adequate energy intake, and can induce weight loss. Insulin sensitivity is impaired by short-term, complete energy restriction, but the effects of IER are not well known. In randomised order, fourteen lean men (age: 25 (sd 4) years; BMI: 24 (sd 2) kg/m2; body fat: 17 (4) %) consumed 24-h diets providing 100 % (10 441 (sd 812) kJ; energy balance (EB)) or 25 % (2622 (sd 204) kJ; energy restriction (ER)) of estimated energy requirements, followed by an oral glucose tolerance test (OGTT; 75 g of glucose drink) after fasting overnight. Plasma/serum glucose, insulin, NEFA, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP) and fibroblast growth factor 21 (FGF21) were assessed before and after (0 h) each 24-h dietary intervention, and throughout the 2-h OGTT. Homoeostatic model assessment of insulin resistance (HOMA2-IR) assessed the fasted response and incremental AUC (iAUC) or total AUC (tAUC) were calculated during the OGTT. At 0 h, HOMA2-IR was 23 % lower after ER compared with EB (P<0·05). During the OGTT, serum glucose iAUC (P<0·001), serum insulin iAUC (P<0·05) and plasma NEFA tAUC (P<0·01) were greater during ER, but GLP-1 (P=0·161), GIP (P=0·473) and FGF21 (P=0·497) tAUC were similar between trials. These results demonstrate that severe energy restriction acutely impairs postprandial glycaemic control in lean men, despite reducing HOMA2-IR. Chronic intervention studies are required to elucidate the long-term effects of IER on indices of insulin sensitivity, particularly in the absence of weight loss.

• Publisher: Cambridge University Press
• Subject: Adult / Area Under Curve / blood glucose / Blood Glucose - analysis / blood serum / Body fat / body mass index / Body weight loss / Caloric Restriction - methods / Chronic illnesses / Diabetes / Diet / Energy / Energy balance / Energy Intake / Energy Metabolism / Energy requirements / Exercise / Fasting / Fibroblast growth factors / Fibroblast Growth Factors - metabolism / Fibroblasts / free fatty acids / Gastric Inhibitory Polypeptide / Gastroenterology / Glucagon / Glucagon-like peptide 1 / Glucagon-Like Peptide 1 - blood / Glucose / Glucose - metabolism / Glucose tolerance / Glucose Tolerance Test / glucose tolerance tests / glycemic control / Growth factors / Healthy Volunteers / Humans / Insulin / Insulin - blood / Insulin Resistance / Laboratories / Long-term effects / Male / males / Meals / men / Metabolism / Metabolism and Metabolic Studies / nutritional intervention / Obesity / Obesity - metabolism / Peptides / Physical fitness / Postprandial Period / Sensitivity / Systematic review / Weight control / Weight Loss / Young Adult