Very-Low-Carbohydrate Diet for Prediabetes and Obesity

Overview

Prediabetes is a condition where blood sugar is higher than normal but not yet high enough to be called type 2 diabetes. It is common in adults who are overweight or obese, and without treatment it often progresses to diabetes over time. This study looks at whether following a very-low-carbohydrate diet for 12 weeks can help adults with prediabetes and obesity lose weight, reduce body fat, and improve how well their body responds to insulin, compared with standard dietary advice. Adults aged 30 to 65 with obesity and newly diagnosed prediabetes are invited to take part. Participants are randomly assigned to one of two groups: one follows a very-low-carbohydrate diet with support from a dietitian, and the other receives standard dietary advice without a specific carbohydrate limit. Both groups are followed for 12 weeks, during which their weight, body composition, blood sugar, insulin levels, cholesterol, and kidney function are checked. The study aims to find out whether the very-low-carbohydrate diet leads to greater improvements in weight, body fat, and insulin sensitivity than standard advice, and whether it is safe and practical to follow in everyday life. The findings may help doctors and dietitians offer more effective ways to prevent prediabetes from progressing to type 2 diabetes.

Obesity and prediabetes frequently coexist and share a common pathophysiological pathway: excess visceral adiposity promotes chronic low-grade inflammation and insulin resistance, accelerating progression from normoglycaemia to prediabetes and ultimately to type 2 diabetes mellitus (T2DM). While carbohydrate-restricted dietary interventions have demonstrated efficacy for weight loss and glycaemic improvement in patients with established T2DM and diabetic kidney disease, their effects have not been well characterised in the earlier, potentially reversible stage of prediabetes, where intervention may carry the greatest preventive value. This single-centre, randomized controlled trial evaluates the effects of a 12-week very-low-carbohydrate diet (VLCBD, less than 50 g carbohydrate/day) compared with standard dietary advice (no specific carbohydrate restriction) in adults with obesity and prediabetes attending a tertiary endocrine outpatient clinic in Malaysia. Both study arms receive individualised caloric intake based on ideal body weight, structured dietary counselling, and food diaries for adherence monitoring. The study compares the two dietary approaches with respect to anthropometric and body composition changes, insulin resistance, and the safety and feasibility of the VLCBD approach over the 12-week intervention period, with assessments at baseline and at Week 12. Findings are intended to inform whether carbohydrate restriction is a feasible, safe, and effective dietary strategy for reducing cardiometabolic risk and preventing progression to type 2 diabetes in adults with prediabetes and obesity - a population not directly addressed by prior low-carbohydrate diet trials, which have been conducted mainly in patients with established diabetes.