Metabolic outcomes after an 8 weeks low-calorie-diet in overweight, pre-diabetic individuals: the role of gender in the PREVIEW study

Abstract

Background & Aims: Lifestyle intervention remains the corner stone in prevention and management of type-2 diabetes (T2D). The PREVIEW intervention study (www.previewstudy.com) is to date the largest, multinational study with the aim of preventing T2D among pre-diabetic individuals with a combination of diet, physical activity and behavior modification. Initially, all participants follow a formula low-calorie diet (LCD) to achieve a significant weight loss (≥8% of initial body weight, BW). Although the majority of participants in LCD weight loss studies are women, very little attention has been paid to the role of gender. Objectives: To compare the effect of 8 weeks’ LCD on weight loss and metabolic outcomes between pre-diabetic men and women. Material & methods The participants received LCD [810 kcal daily] for 8 weeks (Cambridge Weight Plan®). Data from participants who achieved 8% weight loss were included in the analysis. Two-sided t-tests were used throughout. Linear regressions were applied to test correlations. Results: Of 2,326 individuals eligible for the LCD period, a total of 1,842 (79%) participants (1,225 women and 617 men) completed the weight loss phase successfully. At baseline, mean (±SD) age was 51.6±11.6 years, BMI 35.3±6.5 kg/m2, fasting plasma glucose 6.2±0.7 mmol/L, and fasting serum insulin 13.4±7.8 mU/L. Average weight loss was 10.6+/-4.0 kg, with men losing 12.7+/-4.2kg and women 9.6+/-3.4 kg (difference between gender, P < 0.001). The men lost 11.7+/-3.5% of initial BW where the women lost 10.2+/-3.1% (P < 0.001). Fasting plasma glucose decreased by 0.57+/-0.7 mmol/L in men, and by 0.37 +/-0.6 mmol/L in women (P < 0.001). Fasting serum insulin decreased by 5.8+/-7.4 mU/L in men and by 3.8+/-5.4 mU/L in women (P < 0.001). The linear model showed an association of the weight loss percentage as well as gender on the changes in glucose and insulin. Conclusion: An 8 weeks’ LCD intervention resulted in a marked decrease in body weight, fasting glucose and insulin among pre-diabetic subjects. Significantly larger decreases were seen in men versus women. Funding EU FP7, grant agreement 312057; NHMRC – EU Collaborative Grant, AUS; NZ Health Research Council (14/191), UoA Faculty Research Development Fund; The Cambridge Weight Plan has kindly donated all LCD products.