Body composition is heavily influenced by which factors?

• A. Hydration
• B. Diet and Exercise
• C. Sleep
• D. Genetics

Answer: (B)

The main factor shaping body composition is the combination of what you eat and how you train. Diet provides the energy and nutrients that determine fat stores and the building blocks for lean tissue, while exercise—especially resistance training—stimulates muscle growth and helps preserve lean mass. When you create a sustainable energy deficit through a balanced diet and regular exercise, fat mass tends to decrease and body composition improves. Conversely, consistent energy surplus can increase fat, and without resistance training, gains in lean mass are limited.

Hydration can affect short-term body weight and the appearance of fullness or measurement results, but it doesn’t drive long-term changes in fat versus lean tissue. Sleep influences hormones that regulate appetite and metabolism, which can affect adherence and overall energy balance, but it’s secondary to the direct impact of diet and activity. Genetics sets a ceiling and baseline tendencies, yet lifestyle choices largely shape actual body composition outcomes.