Discussion
age-dependent loss of muscle mass, sarcopenia, loss of muscle mass, overweight or obesity, weight loss
METABOLIC SYNDROME, SARCOPENIA
Results from this interim analysis of an ongoing primary prevention RCT indicate that a 3-year weight-loss intervention based on an energy-reduced MedDiet and PA, compared with advice to follow the MedDiet without weight-loss goals, resulted in significant improvements in body composition in middle-aged and older adults with chronic health conditions. In particular, we found that this multifactorial lifestyle intervention was effective in reducing total body fat and visceral fat. In addition, the lifestyle intervention led to an attenuation of age-related decreases in lean mass.In the present study, participants from both groups lost total fat mass in absolute amount, and in parallel, total fat mass relative to total body mass. The decrease in fat mass was small and relatively stable over the follow-up period in the control group. In contrast, in the intervention group, fat mass decreased appreciably, particularly during the first year of the trial, and it was partially regained in the period up to the third year of the trial. Participants in the intervention group showed greater reductions in fat mass (both in grams and percentage of body mass) than those in the control group over the entire follow-up time.We found that only participants from the intervention group decreased grams of visceral fat mass, while in the control group the mass of this fat depot was unchanged over time. The reduction observed in the intervention group did not seem to be independent from changes in total fat mass, as there was no effect of the PREDIMED-Plus intervention on percentage of visceral fat in relation to total fat mass nor on the ratio android to gynoid fat mass. This could indicate that greater loss of total fat mass over time is necessary to mobilize visceral fat mass storage in older adults with overweight or obesity and metabolic syndrome. Even though visceral fat constitutes a small portion of total body fat, the size of the effects of the PREDIMED-Plus intervention on total and visceral fat mass was comparable, as observed in analyses using normalized into Besides fat mass, intentional weight loss is usually associated with loss of lean mass, similar to the process of aging. In this regard, we observed that both the control and intervention groups showed significant loss of lean mass in the absolute amount between baseline and 3-year follow-up time, with the effect being greater for the participants in the intervention group. In comparison with the controls, participants in the intervention group showed increases in the percentage of total lean mass in relation to the total body mass (lean + fat + bone mass) and the total lean mass to total fat mass ratio. This finding is noteworthy as it represents a more favorable body composition profile sustained during a 3-year period, suggesting that participants in the intervention group achieved weight loss preferentially at the expense of total fat rather than lean mass. Lifestyle interventions for weight loss should include strategies preserving lean body mass to delay age-dependent loss of muscle mass or sarcopenia (loss of muscle mass and strength),Despite the fact that the magnitude of body composition changes was rather mild, although statistically significant, we found that these changes were likely of clinical relevance (based on attainment of at least 5% improvements in baseline values). In particular, we found that for every 12 or 17 persons receiving an intervention with energy-reduced MedDiet and PA, as opposed to advice to follow ad libitum MedDiet, 1 additional individual would improve visceral fat mass (n = 12) or percentage of fat and lean mass (n = 17). In the same direction, previous findings from the pilot study of the PREDIMED-Plus trial