Alternative Dietary Strategies to Modulate Obesity and Improve Metabolic Health in Aging: A Comparative Narrative Review

In aging, chronic diseases such as obesity accelerate metabolic dysfunction through chronic inflammation and insulin resistance. This review compared three different dietary strategies to evaluate their mechanisms and benefits for metabolic health and longevity. A comprehensive database search was conducted, selecting studies in animal models and in humans with or without obesity which have been published since 2004. Fasting-mimicking diets reduce IGF-1, promote autophagy, and improve insulin sensitivity, although long-term adherence remains a challenge. Time-restricted feeding synchronizes food intake with circadian rhythms, benefiting inflammation, glycemic control, and body composition. Protein and amino acid restriction, particularly methionine and branched-chain amino acids, modulates mTOR and reduces oxidative stress but requires adjustments in older adults. According to the available evidence, each intervention offers a non-invasive and adaptive approach to mitigating the effects of aging, provided it is applied in a personalized manner with appropriate follow-up.