What is the ideal body composition for a woman in terms of percentage of body fat, in relation to optimal health, cancer risk, recurrence risk, and inflammation?

From the Guidelines

The ideal body composition for a woman in terms of percentage of body fat, in relation to optimal health, cancer risk, recurrence risk, and inflammation, is between 21% and 33%.

Key Points

• This range is associated with a lower risk of chronic diseases, such as heart disease, diabetes, and certain types of cancer, including breast cancer 1.
• A body fat percentage above 33% is considered obese and increases the risk of these diseases, while a percentage below 21% may indicate underweight or malnutrition 1.
• Maintaining a healthy weight and body composition through a balanced diet and regular physical activity is crucial for reducing the risk of cancer recurrence and improving overall health 1.
• The American Cancer Society recommends that cancer survivors strive to achieve and maintain a healthy weight, with a BMI between 18.5 and 25.0 kg/m², and engage in moderate physical activity to reduce the risk of cancer recurrence and improve survival rates 1.
• Assessing body composition is essential for identifying individuals at risk of malnutrition or obesity, and for monitoring the effectiveness of interventions aimed at improving body composition and reducing disease risk 1.
• A combination of dietary and physical activity strategies can help individuals achieve and maintain a healthy weight and body composition, reducing the risk of chronic diseases and improving overall health 1.

From the Research

Ideal Body Composition for Women

The ideal body composition for women in terms of percentage of body fat is a topic of ongoing research. Several studies have investigated the relationship between body fat percentage and health outcomes, including cancer risk, recurrence risk, and inflammation.

• A study published in 1996 2 suggested that the best body fat percentages for women averaged between 20% and 30%.
• Another study published in 2000 3 developed a new approach for establishing healthy percentage body fat ranges based on body mass index (BMI) guidelines.
• A 2015 study 4 found that physical activity was associated with lower body fat percentage, trunk fat mass and percentage, waist and hip circumference, and waist-to-hip ratio in both premenopausal and postmenopausal women.
• A 2021 study 5 investigated the influence of body fatness on the associations of body composition and energy expenditure with energy intake in healthy women, and found that body fat percentage moderated the associations of resting metabolic rate and total daily energy expenditure with mean free-living 24-hour energy intake.

Body Fat Percentage and Health Outcomes

While there is no single ideal body fat percentage for all women, research suggests that maintaining a healthy body fat percentage can reduce the risk of chronic diseases, including cancer and inflammation.

• A study published in 2014 6 developed a new predictive equation for evaluating women's body fat percentage and obesity-related cardiovascular disease risk.
• The 1996 study 2 noted that most weight-associated health problems result from a cascade of events associated with abnormal blood concentrations of insulin, glucose, or lipids that occur when fat cells become full and insulin-insensitive, and lose their protective functions.

Key Findings

Key findings from the studies include:

• Body fat percentage is a better predictor of obesity-related risk diseases than BMI and BAI 6.
• Physical activity is associated with lower body fat percentage and improved health outcomes 4.
• Body fat percentage moderates the associations of energy expenditure with energy intake in healthy women 5.
• Healthy body fat percentages for women averaged between 20% and 30% 2.