Dietary and Behavioral Strategies for Weight Loss and Weight Loss Maintenance: A Narrative Review

Background: Obesity is a multifactorial chronic disease associated with increased risk of metabolic disorders, reduced quality of life, and rising healthcare costs. Although weight reduction is achievable through various dietary approaches, maintaining the achieved results remains a major clinical challenge. This review aims to identify and discuss dietary, behavioral, and lifestyle strategies that support long-term weight loss and weight maintenance. Methods: A narrative literature review was conducted in two stages using PubMed, Scopus, and Google Scholar. The search included peer-reviewed studies published between 2015 and 2025 focusing on individuals with overweight and obesity. Randomized controlled trials, observational studies, systematic and narrative reviews, and meta-analyses discussing short-term and long-term weight loss outcomes and factors influencing the maintenance of reduced body weight were included. Results: Multiple nutritional strategies, including continuous and intermittent energy restriction, very low-calorie diets, and macronutrient modification, can be effective for weight reduction. However, long-term outcomes are primarily dependent on adherence and consistent implementation of recommendations. Behavioral and psychological factors, such as emotional eating, dietary fatigue, and unrealistic expectations, often contribute to weight regain. Social support, personalized dietary strategies, and sustainable lifestyle habits are key determinants of maintaining weight loss. The current evidence base is limited by the scarcity of long-term follow-up studies and high methodological variability across interventions. Conclusions: Long-term weight management requires a comprehensive, individualized approach that integrates dietary strategies with behavioral and lifestyle support. Strengthening adherence and addressing psychological and environmental factors may significantly improve the effectiveness and durability of obesity treatment.