Losing Weight: Men and Women React Differently to Diets

Introduction

In an ongoing study, an international research team has examined the effects of different diets on 2,224 individuals with overweight or obesity (median BMI over 34.7) from eight different regions over a period of eight weeks. While the primary aim of the study is to compare two different diets (high protein content versus low protein content) and two sports programs (high versus low intensity) over three years, the initial findings revealed intriguing differences in how men and women respond to diets.

Gender Differences in Weight Loss

The results of the study, published in the journal Diabetes, Obesity & Metabolism, indicate that men tend to lose more weight than women when subjected to a special reduction diet (810 kcal daily). According to Pia Christensen of the University of Copenhagen, during the first eight weeks, men lost an average of 11.8 kilograms, whereas women lost only 10.2 kilograms, a difference of 16 percent. Furthermore, men lost 2.2 kilograms more fat and 1.3 kilograms less fat-free mass than women.

The men's cardiovascular systems also responded differently, with a greater reduction in insulin production (indicator: C-peptide) and a more significant decrease in heart rate. Additionally, the Z-score of the metabolic syndrome, which evaluates risk factors such as hip circumference, blood pressure, and cholesterol, improved for men. For women, there was a significant decrease in hip circumference and pulse pressure, which researchers consider positive. However, the decrease in HDL (high-density lipoprotein) cholesterol and bone mass, combined with the reduction in fat-free mass, is seen as an unfavorable sign.

The reasons behind these gender differences in response to diets remain unclear, according to the scientists.

Diabetes Risk and Insulin Resistance

Despite the differences in weight loss and metabolic responses, one finding was consistent across both genders: the effect on insulin resistance, a major risk factor for Type 2 diabetes. All participants reported increased fasting blood sugar or impaired glucose tolerance, indicating the onset of Type 2 diabetes. This allowed scientists to closely examine the impact of dietary changes on diabetes risk.

The outcome showed a significant improvement in blood sugar levels for both sexes, with one-third of participants no longer meeting prediabetes criteria after eight weeks. Whether these improvements will prevent the development of Type 2 diabetes in the long term remains to be seen, as the study is set to continue for a total of three years and is expected to be completed by the end of 2018.

Conclusion

This study highlights the importance of considering gender-specific responses in dietary interventions for weight loss and metabolic health. Further research is needed to understand the underlying mechanisms driving these differences and to optimize diet and exercise programs for both men and women.

References

Christensen, P. et al. (2018). 'Losing Weight: Men and Women React Differently to Diets'. Diabetes, Obesity & Metabolism.