Combining Short-Term Interval Training with Caloric Restriction Improves ß-Cell Function in Obese Adults

Abstract

Although low-calorie diets (LCD) improve glucose regulation, it is unclear if interval exercise (INT) is additive. We examined the impact of an LCD versus LCD + INT training on ß-cell function in relation to glucose tolerance in obese adults. Twenty-six adults (Age: 46 ± 12 year; BMI 38 ± 6 kg/m2) were randomized to 2-week of LCD (~1200 kcal/day) or energy-matched LCD + INT (60 min/day alternating 3 min at 90 and 50% HRpeak). A 2 h 75 g oral glucose tolerance test (OGTT) was performed. Insulin secretion rates (ISR) were determined by deconvolution modeling to assess glucose-stimulated insulin secretion ([GSIS: ISR/glucose total area under the curve (tAUC)]) and ß-cell function (Disposition Index [DI: GSIS/IR]) relative to skeletal muscle (Matsuda Index), hepatic (HOMA-IR) and adipose (Adipose-IRfasting) insulin resistance (IR). LCD + INT, but not LCD alone, reduced glucose and total-phase ISR tAUC (Interactions: p = 0.04 and p = 0.05, respectively). Both interventions improved skeletal muscle IR by 16% (p = 0.04) and skeletal muscle and hepatic DI (Time: p < 0.05). Improved skeletal muscle DI was associated with lower glucose tAUC (r = −0.57, p < 0.01). Thus, LCD + INT improved glucose tolerance more than LCD in obese adults, and these findings relate to ß-cell function. These data support LCD + INT for preserving pancreatic function for type 2 diabetes prevention.

Sources of Inter-individual Variability in the Therapeutic Response of Blood Glucose Control to Exercise in Type 2 Diabetes: Going Beyond Exercise Dose

“… Bouchonville et al (2014) reported that fasting glucose, and glucose AUC and insulin sensitivity measured during OGTT were more robustly improved following 12-months of diet-induced weight loss (10% of body weight) plus exercise (90-min of combined aerobic and resistance, thrice weekly) when compared to either weight loss or exercise alone, in 100 obese individuals. The additional benefit conveyed by exercise plus diet-induced weight loss is supported by other recent work ( Weiss et al, 2015 ; Francois et al, 2018 ). But the importance of exercise alone is also underpinned by outcomes from the IDES trial: Balducci et al (2012) found that the magnitude of increase in fitness following exercise training (twice weekly supervised aerobic and resistance training plus exercise counseling) predicts improvement of cardiometabolic risk factors including HbA1c, independent of weight loss.…”

Pre-operative aerobic exercise on metabolic health and surgical outcomes in patients receiving bariatric surgery: A pilot trial

“…Through a series of recent studies, we evaluated the effect of a 2-week LCD (about 1200kcal/d) based on pre-operative standard medical care nutrition recommendations for adults undergoing bariatric surgery, with or without an energy deficit matched aerobic exercise intervention. Results collectively indicate that LCD+exercise increased aerobic fitness, maintained post-prandial carbohydrate (CHO) utilization, and improved glucose tolerance when compared with LCD alone [19,20]. These findings suggest that exercise may augment the ability of a LCD to enhance insulin-regulated glycemia and metabolic health.…”

Endothelial function following interval exercise plus low‐calorie diet treatment in obese females

“…Obese females (age: 47.2 ± 2.6 years, BMI: 37.5 ± 1.3 kg/m 2 ) were recruited via advertisements in the local community, and some data were previously reported (Francois et al, ; Gilbertson et al, ). All participants completed a health history questionnaire and screening.…”

“…Metabolic control for 48 h prior to testing was implemented as previously reported for this trial (Francois et al, ; Gilbertson et al, ). In brief, subjects were instructed to refrain from caffeine and alcohol consumption as well as strenuous activity 48 h prior to testing.…”