Answer:
He should have a balanced diet, healthy sleeping pattern and daily exercise.
Explanation:
High energy in the diet (excess calories from <em>sugar, starches or fat</em>) is the main factor that determines obesity epidemic. Alcohol consumption and tobacco use should be minimal if not non-existent. Physical activity is also a big bonus. Sleeping at least 8 hours a day and drinking 2 liters of water together with balanced diet can give amazing results.
By increasing physical activity, reducing intakes of foods high in fat and drinks high in sugars, he can also prevent unhealthy weight gain along with high risks of developing chronic diseases (CAD, stroke, diabetes, many cancers) that are preventable.