Body Composition Is It All About Body Fat?
Heard these phrases?
“Want to get toned but not bulky”
“Want to gain muscle and lose fat”
You do these through body composition changes…
Most people immediately think of body fat when the term body composition is used. And usually only concerned about their body fat percentage.
Body Mass Index (BMI) is often thought of as a measure of body composition as it is used to determine if an individual’s weight is healthy or unhealthy based on height and weight. BMI does not consider age, gender, body type nor measures body composition, which determines the amount of fat and muscle an individual has. BMI is limited and, often times show a high BMI, classified as obese, in athletic populations that have higher amounts of muscle without high body fat. Body composition is a more effective and accurate way to determine healthy or unhealthy body weight and body fat.
Body composition is very complex, and there are various models that contain different components. For this blog, I will discuss the two-compartment model, which includes fat mass and fat free mass, also referred as lean body mass, (organs, muscle, bone, water).
Why measure body composition?
1. It determines if an individual has too little or too much body fat, which can cause concerns for long-term health. Body fat consists of essential body fat and storage fat.
Essential body fat is necessary to survive and is present in nerve tissues, bone marrow, and organs. Typically, women require 10-13% and men 2-5% essential fat. Women have higher essential fat due to the production of sex-specific hormones.
Storage fat is an energy reserve that accumulates when excess energy is ingested and decreases when more energy is expended than consumed. To prevent excess storage fat, it is recommended to consume 20-35% of your total daily calories from fat, limit saturated fat to 10% of total daily calories, and avoid trans-fat.
2. Assess lean mass (muscle) over time, which can be a performance indicator for athletes, who need adequate muscle to perform at a level necessary to compete within their specific sport.
3. To determine effectiveness of an intervention, including nutrition, physical activity, lifestyle, etc.
How do I measure body composition?
There are several methods to measure body composition. Most commonly used due to low cost, availability and ease of operation are skinfold thickness and bioelectrical impedance analysis (BIA).
More advanced methods that have higher levels of accuracy, costs and limited availability are
Hydrodensitometry (underwater weighing)
Air Displacement Plethysmography (Bod Pod)
Dual Energy X-ray Absorptiometry (DXA)
How often should I measure body composition?
Minimally measure every three months
Average body fat percentage for the general population based on age (years old)
Up to 30: Males: 9-15%; Females: 14-21%
30-50: Males: 11-17%; Females: 15-23%
>50: Males: 12-19%; Females: 16-25%
Ref: Sports Nutrition, 3rd Ed. by Asker Jeukendrup & Michael Gleeson
What is considered too much body fat?
Varies by gender, age and sport
Overweight: Males = 21-24%; Females = 31-36%
Obese: Males = >24%; Females = >37%
Ref: Sports Nutrition, 3rd Ed. by Asker Jeukendrup & Michael Gleeson
What does it mean to make body composition changes?
Changes in fat mass and/or lean body mass.
Examples:
Losing fat mass while maintaining or gaining lean body mass
Maintaining fat mass while gaining lean body mass
When to make body composition changes for athletes?
Altering body composition during the season is not recommended as macronutrient distribution is often not high enough in carbohydrates to meet optimal performance needs. Off-season is the time to address body composition changes. Also, when attempting to lose weight or fat mass, there is always a potential to lose lean body mass, which can negatively affect an athlete’s performance during the competitive season.
How to make body composition changes?
Prioritize protein including it at meals and snacks
Match carbohydrate intake to training levels. For rest or low intensity days reduce carbohydrate intake, while on high-intensity days increase carbohydrate intake
Consume high fiber foods such as whole grains, fruits and vegetables
Remember that liquid calories like sodas and sugary beverages add up in sugar and excess calories (if you aren’t competing or sweating profusely, you don’t need sports drinks like Gatorade)
Ready to make body composition changes? Work with a sports dietitian to establish a plan tailored to your individual needs based on training schedule and body weight or body composition goals.