Fat loss mainly conveys the benefits of caloric restriction for people living with type 2 diabetes. The literature is equivocal regarding whether exercise facilitates fat loss during caloric restriction. This analysis aimed to assess the dose–response effects of exercise in combination with a caloric restriction on fat mass (FM) and FM percentage (FM%) in persons with diagnosed type 2 diabetes.

In this secondary analysis of a 4-armed randomized trial, 82 persons living with type 2 diabetes were randomly allocated to the control group (CON) (n = 21), diet control (DCON) (25% caloric restriction; n = 20), diet control and exercise 3 times per week (MED) (n = 20), or diet control and exercise 6 times per week (HED) (n = 21) for 16 weeks. The primary analysis was the change in FM% points. Secondary analyses included fat-free mass and visceral adipose tissue (VAT) volume (cm3).

FM% decreased compared to CON by a mean difference of –3.5% (95% confidence interval (95%CI): –5.6% to –1.4%), –6.3% (95%CI: –8.4% to –4.1%), and –8.0% (95%CI: –10.2% to –5.8%) for DCON, MED, and HED, respectively. Compared to DCON, MED, and HED decreased FM% by –2.8% (95%CI: –4.9% to –0.7%) and –4.5% (95%CI: –6.6% to –2.4%), respectively. The difference in FM% between HED and MED was –1.8% (95%CI: –3.9% to 0.4%). DCON and MED decreased fat-free mass compared to CON, whereas HED preserved fat-free mass (–0.2%; 95%CI: –2.0% to 1.7%). Compared to CON, VAT volume decreased by –666.0 cm3 (95%CI: –912.8 cm3 to –385.1 cm3), –1264.0 cm3 (95%CI: –1679.6 cm3 to –655.9 cm3), and –1786.4 cm3 (95%CI: –2264.6 cm3 to –1321.2 cm3) more for DCON, MED, and HED, respectively. HED decreased VAT volume more than DCON (–1120.4 cm3; 95%CI: –1746.6 cm3 to –639.4 cm3) while the remaining comparisons did not reveal any differences.