GC4.307 - Gender-related differences in weight loss induced by a Very Low Calorie Ketogenic Diet protoco

Background: Sex-related biological factors and sociocultural gender aspects influence weight loss. However, most dietary intervention stud- ies never explored gender-related outcomes. Investigating whether very low calorie ketogenic diet (VLCKD) outcomes differ between men and women is important for developing gender-specific programs of precision nutrition. Differences in outcomes after weight loss have been reported previously, with men commonly losing more body weight and adipose tissue than women. Aim: We aimed to compare anthropometric and metabolic effects of a VLCKD nutritional program for six weeks in a cohort of men and women. Materials-Methods: 72 patients with obesity and insulin resistance [22 males and 50 females, HOMA index ≥ 2.5, age 55.6±6.7 years, BMI 35.23±4.1 kg/m 2] were consecutively selected among those referring to our nutrition center, followed a VLCKD for 6 weeks (≤800 kcal/day). Anthropometric indexes, blood and urine chemistry, including parame- ters of renal, hepatic, glucose and lipid metabolism were evaluated. Results: At baseline, as expected, male patients showed a higher weight (104.5±13.5 kg) than female patients (94.4±11.7 kg, p=0.002), as well as a higher waist circumference (112.5±7.3 cm vs 102.5±8.7, p=0.001). At baseline, 45.5% of men and only 8% of women suffered from type 2 diabe- tes mellitus (p=0.001). Male patients showed higher fasting insulin (17.75 μU/mL) and HOMA index (4.7) values than female patients (p=0.007 and p=0.022, respectively). Body weight (-8.6±2.6, p<0.001), BMI (-3.2±1.0, p<0.001), waist circumference (-7.3±3.2, p<0.001), total and low-density lipoprotein cholesterol (-38.1±22.6, p<0.001; -30.3±24.1, p<0.001 respec- tively] and triglycerides (-38.3±37.9, p<0.001) markedly decreased in female participants during the VLCKD. Also, a significant reduction in body weight (-10.2±3.0, p<0.001), BMI (-3.3±09, p<0.001), waist circum- ference (-7.1±2.7, p<0.001), total and lowdensity lipoprotein cholesterol (-49.6±37.7, p<0.001; -34.5±21.9, p<0.001, respectively) and triglycerides (-56.5±104.3, p<0.001) was observed in male participants. When compar- ing groups, it was found that males lost 1.65±0.72 kg more than females (CI 95% [0.21;3.1],p=0.025). There was also a greater reduction in systolic and diastolic blood pressure in the male group (-7,2±3,4 mmHg, p=0,044; -7,3±2,8 mmHg, p=0,016 respectively). Finally, a greater reduction in fasting insulin (-8,3±3,4 μU/mL, p=0,023) and HOMA index (-2,9±1,3, p=0,046) was observed in the male group at the end of VLCKD. Conclusions: Six weeks of VLCKD were accompanied by significant improvements in anthropometry, blood pressure, and metabolic profile in women and men with obesity and insulin resistance. Men lost signifi- cantly more body weight than women and showed a higher reduction in HOMA index, fasting insulin, and blood pressure. This is the first study showing significant gender-related differences in the effects of a VLCKD