Diet-exercise combo most effective for lasting weight loss: ICMR-NIN

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Low-calorie diets were found to be the most effective for short-term weight loss, resulting in an average reduction of 2.64 kg within the first three months. | Photo Credit: Representational Photo

Combining healthy dietary practices with regular physical activity is the most effective non-drug strategy for achieving sustained weight loss and improving key metabolic health indicators among adults with overweight or obesity, according to a major review by the ICMR-National Institute of Nutrition (NIN) here.

The findings, published in the international journal Obesity Pillars , are based on an umbrella review that analysed evidence from 112 systematic reviews and meta-analyses covering 2,332 randomised controlled trials and more than 5.07 lakh participant observations across over 50 countries.

The review, led by ICMR-NIN scientists Mahesh Kumar Mummadi and Samarasimha Reddy, compared the impact of dietary interventions, physical activity, lifestyle changes and combined approaches on weight management and cardiometabolic health.

Researchers found that all major non-pharmacological interventions produced statistically significant, though generally modest, reductions in body weight and Body Mass Index (BMI). However, the combination of diet and physical activity delivered the most sustained results, with participants losing an average of 3.68 kg beyond 12 months compared with control groups.

Low-calorie diets were found to be the most effective for short-term weight loss, resulting in an average reduction of 2.64 kg within the first three months. Physical activity alone led to smaller reductions in body weight, but its benefits increased over longer follow-up periods.

Lifestyle interventions such as behavioural counselling, goal-setting, self-monitoring and health education also showed positive outcomes, with their effectiveness improving over time. Beyond weight loss, the study highlighted significant improvements in metabolic health. The combination of diet and physical activity produced the greatest benefits in blood sugar control, reducing fasting blood glucose levels and insulin resistance after 12 months.

Physical activity emerged as the most effective strategy for lowering blood pressure, reducing systolic blood pressure by about 6.1 mmHg between six and 12 months. Intermittent fasting showed the largest short-term reduction in diastolic blood pressure and supported weight loss for up to a year, although these benefits were not sustained beyond 12 months.

ICMR-NIN director Bharati Kulkarni said the findings underscore the importance of an integrated approach to tackling obesity. “Healthy dietary practices, regular physical activity and behavioural support each have a role, but their combination can provide broader and more sustained benefits.