Regular physical exercise. This protects the brain and the way it processes information. Exercise boosts levels of brain-protective chemicals and reduces stress.

Adequate sleep. A good night’s sleep recharges the brain and allows the body to rest and heal. Our brain consolidates memories while we sleep. Inadequate sleep affects the way our brain cells function and can increase the risk of stroke and depression. About seven to nine hours of sleep a night is ideal.

Balanced diet. Your diet should be low in cholesterol and saturated fat. Studies show that foods rich in omega-3 fatty acids (e.g., fish) are good for the brain.

Social connections. Friendships and social networks are important as we age. Good mood hormones help us create new brain cells and keep them healthy.

Mental workout. Use it or lose it! Keeping the brain active and challenged increases its vitality, generates new brain cells, and bolsters connections and reserves.

After six months, all four diet groups averaged a six-kilogram weight loss, or 7 percent of their original weight, which ever diet they were on. All again began to regain weight after 12 months. After two years, the average weight loss was about four kilograms for all groups. Earlier studies had claimed that higher protein intake reduced appetite and sustained muscle mass better during weight loss. The Harvard researchers’ conclusion: A diet program’s benefits result from the degree to which people stick with them, not from any specified energy reduction formula.