From the Guidelines
Healthy body fat percentages vary by age and gender, with women naturally requiring higher levels than men, and the ideal range for men is 8-24% and for women is 21-35% across different age groups. For men aged 20-39, a healthy range is typically 8-19%, increasing to 11-21% for ages 40-59, and 13-24% for those 60 and older 1. For women aged 20-39, the healthy range is 21-32%, rising to 23-33% for ages 40-59, and 24-35% for women 60+ 1. These percentages reflect the body's changing composition as we age, with a natural tendency to gain fat and lose muscle mass. Essential fat (needed for basic physiological functions) is about 3-5% for men and 10-13% for women. Body fat serves important functions including energy storage, organ protection, temperature regulation, and hormone production. Measuring body fat can be done through various methods including DEXA scans, bioelectrical impedance, skinfold calipers, or body circumference measurements. Rather than focusing solely on weight or BMI, maintaining appropriate body fat levels through regular exercise and balanced nutrition contributes significantly to overall health and longevity, as supported by the American Cancer Society guideline for diet and physical activity for cancer prevention 1. Some key points to consider are:
- Achieve and maintain a healthy body weight throughout life
- Keep body weight within the healthy range, and avoid weight gain in adult life
- Excess body fat (overweight and obesity) occurs from energy imbalance as a result of excess energy intake and low energy expenditure
- Aerobic physical activity, including walking, is associated with a lower risk of excess body fatness, whereas sedentary behaviors and greater screen time are associated with higher risk.
From the Research
Ideal Body Fat Percentage by Age
The ideal body fat percentage varies by age, sex, and race-ethnicity. According to the study by 2, the percentage of body fat that corresponds to a BMI of 18.5,25,30,35, and 40 across age and racial-ethnic groups ranges from:
- 12.2% to 19.0% for men aged 18-29 years
- 22.6% to 28.0% for men aged 18-29 years
- 27.5% to 32.3% for men aged 18-29 years
- 31.0% to 35.3% for men aged 18-29 years
- 33.6% to 37.6% for men aged 18-29 years And for women:
- 24.6% to 32.3% for women aged 18-29 years
- 35.0% to 40.2% for women aged 18-29 years
- 39.9% to 44.1% for women aged 18-29 years
- 43.4% to 47.1% for women aged 18-29 years
- 46.1% to 49.4% for women aged 18-29 years
Factors Affecting Body Fat Percentage
Several factors affect body fat percentage, including:
- Sex: Women tend to have higher body fat percentages than men 2
- Age: Older adults tend to have higher body fat percentages than younger adults 2
- Race-ethnicity: Non-Hispanic blacks tend to have lower body fat percentages than non-Hispanic whites and Mexican Americans 2
- BMI: Body fat percentage is related to BMI, with higher BMIs corresponding to higher body fat percentages 3, 2
Measuring Body Fat Percentage
Measuring body fat percentage can be challenging, especially in clinical settings. According to the study by 4, anthropometric equations can be used to estimate body fat percentage, but their accuracy varies depending on the equation used and the population being studied. The study found that the best equations for estimating body fat percentage in older adults were those developed by Lean et al. (1996) for men and Deurenberg et al. (1991) for women. However, even these equations had limitations and did not always agree with the gold-standard method of dual-energy X-ray absorptiometry (DXA) 4.
General Guidelines
General guidelines for body fat percentage have been proposed, with ranges of 12-20% for men and 20-30% for women considered healthy 5. However, these guidelines may not be applicable to everyone and should be used as a screening tool rather than a strict guideline 5.