Multiple studies have shown that long-term calorie restriction can reduce metabolic function and slow the cellular aging process — in rats! Human trials have been limited. A 2019 study in The Lancet showed that people who reduced their calorie intake by 12 percent had lower blood pressure and cholesterol, increased insulin sensitivity and lower inflammation. The problem? The study covered only 238 people over two years, and the oldest among them were 50. Plus, calorie-restriction diets can cause muscle loss, which in turn can result in rebound weight gain and other unhealthy outcomes.

Women feel worse about their health than men do. Across all age groups, 70 percent of men rated their mental health as very good or excellent, compared with 54 percent of women. Females worry more about joint pain and sleeping problems, too.