A new study published in JAMA Network Open suggests that coupling a reduced-calorie Mediterranean diet with exercise can reduce body fat while maintaining muscle mass, a combination of particular importance to older individuals.
“The results obtained demonstrate that combining a dietary plan based on the traditional Mediterranean diet with caloric restriction and increased physical activity can partially reverse age-associated changes in body composition in overweight older adults,” lead author Jadwiga Konieczna said.
Given the metabolic relevance of visceral fat and lean mass, the benefits of this type of lifestyle intervention could benefit older people in preventing age-related loss of muscle mass.
The study was conducted by researchers from the Biomedical Research Consortium Network – Physiopathology of Obesity and Nutrition (CIBEROBN), a consortium of 33 working groups under the Spanish Ministry of Science and Innovation, well-known for its research into the benefits of the Mediterranean diet, the prevention of metabolic disorders, childhood and youth obesity and the relationship between obesity and cancer.
Most previous studies on weight loss and improving metabolic alterations associated with abdominal obesity had focused on evaluating their effect on overall body weight, not on body fat distribution, using direct measurements of body composition through imaging techniques.See Also:Health News
Therefore, this study aimed to evaluate the effects of a lifestyle intervention focused on weight loss on changes in overall body composition and individual body regions.
The development of obesity-associated chronic diseases is intricately linked to specific components of body composition.
Excessive visceral fat and the age-related loss of muscle mass have been identified as key factors associated with a heightened risk of various health issues, including cardiovascular disease and type 2 diabetes.
Muscle loss in the elderly is also associated with elevated rates of injury due to the resulting reduction in skeletal support and an increased risk of accidents such as falls.
Consequently, strategies addressing these specific body composition components, extending beyond conventional weight management, are essential for long-term health improvement.
The Mediterranean diet, especially when energy-reduced, is gaining recognition as an effective weight loss and sustained maintenance approach.
The Prevention with Mediterranean Diet (PREDIMED) trial results support that an energy-reduced Mediterranean diet could be optimal for weight loss and cardiovascular disease prevention.
Furthermore, a 2017 review of 18 intervention trials indicated that Mediterranean diet interventions, whether energy-reduced or not, significantly reduce central obesity measures.
Despite challenges in related trials, such as indirect measurement methods or small sample sizes, the positive effects of physical exercise on visceral fat in overweight adults and on muscle mass in older adults have been established.
However, the combined effects of an energy-restricted Mediterranean diet and physical activity on body composition in older individuals have remained unexplored.
The study aimed to ascertain the long-term effects of this lifestyle intervention on age-related changes in overall and regional body composition after the initial three years of the ongoing PREDIMED-Plus randomized clinical trial.
PREDIMED-Plus was chosen because it allowed the researchers to evaluate the impacts of a multifactorial intervention involving an energy-reduced Mediterranean diet, physical activity promotion and behavioral support for weight loss in middle-aged and older adults with metabolic syndrome and initial overweight or obesity.
The trial, conducted across 23 Spanish centers, recruited participants between October 2013 and December 2016. Eligible participants were middle-aged and older men (55 to 75 years old) and women (60 to 75 years old) without prior cardiovascular events, presenting with overweight or obesity and metabolic syndrome.
The intervention group received personalized face-to-face nutritional and behavioral programs, incorporating a 30 percent energy reduction and encouragement to limit specific food consumption. Additionally, they were motivated to increase aerobic physical activity progressively.
Trained dietitians maintained regular contact with participants during the first year, providing group and individual sessions and telephone support. Behavioral and motivational strategies, including self-monitoring and goal setting, were integral.
In contrast, the control group received general advice to follow the traditional Mediterranean diet without specific weight-loss goals.
Comparative analysis between the intervention and control groups revealed that participants in the intervention group were more likely to exhibit five percent or more improvements in all body components at one and three years of follow-up.See Also:Mediterranean Diet Linked to Improved Outcomes in Liver Disease Patients
Notably, these improvements were more pronounced in the first year, with absolute risk reduction percentages for total fat mass, lean mass and visceral fat mass. For instance, for every 12 persons undergoing the intensive lifestyle intervention, one additional individual experienced a clinical improvement in visceral fat mass at year three.
No significant interactions were found between sex and smoking habits for the studied outcomes during the follow-up, but age showed significant interactions.
Younger participants (less than 65 years old) exhibited more substantial beneficial changes in body composition at year one, which were not sustained at year three.
Conversely, older participants (65 or older) showed lower magnitude changes initially but maintained stability over time. Between-group differences were significant only in participants without type 2 diabetes.
Both intervention and control groups experienced absolute and relative loss of total fat mass. Still, the intervention group showed appreciable decreases, especially in the first year, partially regaining it by the third year. The intervention group exhibited greater reductions in fat mass (both grams and percentage of body mass) compared to the control group throughout the follow-up.
Only participants in the intervention group showed decreased visceral fat mass, while the control group showed no change over time.
This reduction appeared related to total fat mass loss, as the intervention did not affect the percentage of visceral fat to total fat mass or the android-to-gynoid fat mass ratio.
Intentional weight loss typically involves lean mass loss, akin to aging. Both groups experienced significant absolute lean mass loss, with the intervention group showing a greater effect.
However, participants in the intervention group displayed increases in the percentage of total lean mass relative to total body mass and the total lean mass to total fat mass ratio, suggesting a more favorable body composition profile over the three years.
Dora Romaguera, the study’s principal investigator, and Jordi Salas-Salvadó, coordinator of the PREDIMED-Plus trial, said that “given the metabolic relevance of visceral fat and lean mass, the benefits of this type of lifestyle intervention could benefit older people in preventing age-related loss of muscle mass, especially if they need to reduce their weight.”
Despite the modest body composition changes, the researchers deemed them clinically relevant, with improvements of at least five percent in baseline values.
However, they stress that continued follow-up is essential to ascertain whether these moderate improvements can effectively prevent cardiovascular events or mortality.