WEIGHT GAIN: IS IT BODY FAT, OR SOMETHING ELSE?

During the festive season and often associated holidays/vacations, it is not unusual to gain some weight. Given a significant proportion of people living in many parts of the world are overweight or obese according to their Body Mass Index (i.e., BMI greater than 25 kilograms/meters squared (kg/m2)), this is often a cause for concern. Should it be?

 

 

In wealthy nations, most people now own a set of bathroom scales for weighing themselves and other members of the family. Some people choose to weigh themselves or family members regularly, and this may become a source of anxiety, particularly after the festive season. 

 

Let’s face it, if we are concerned about weight gain, we are most likely concerned about fat gain – not increasing muscle or bone mass. Excess fat gain – particularly around the middle – can be a concern both aesthetically and metabolically, but gaining muscle or bone is not cause for concern for either reason. 

 

Even if you weigh yourself with no clothes on, the measure in kilograms/pounds is crude. It does not tell you anything about your body composition: how much muscle, bone, fat, etc… you have and how these organs have changed over the festive/holiday/vacation period.

 

Fortunately, technologies such as dual-energy X-ray absorptiometry and bioimpedance analysis are now relatively commonly available, and can estimate whether your festive season weight gain is all fat, or whether you have also increased your activities over the vacation period and have consequently put on some muscle as well (see this month’s What’s New?).

 

If you live in a large town or city in many parts of the world, chances are your local health professional or gym has these technologies (bioimpedance analysers are increasingly common), and you can see if your festive season weight gain is due to fat gain or something else. 

 

If you don’t have access to these technologies, don’t fret, there are some relatively simple alternatives. Waist circumference and the waist to height ratio are useful estimates of abdominal fat gain that anyone can measure at home with a simple tape measure. They measure changes in abdominal fat which is metabolically the most active source of fat tissue in humans, and consequently the underlying driver of increased risk of metabolic conditions like type 2 diabetes, cardiovascular disease and even certain cancers (e.g., colorectal, pancreatic, breast, etc…). 

 

To measure your waist circumference, you simply need a good tape measure. Carefully run the tape measure evenly around your abdomen, halfway between the top of the hip bones and the bottom of the rib cage, and record the result. Ask a family member or friend to help out for best results. 

 

Now check your waist measurement against the appropriate category in the following table: 

 

For people that are very tall or very short, the ratio of waist circumference relative to height (weight : height, or WHR) is a better way of estimating the risk of developing conditions like type 2 diabetes, cardiovascular disease, etc… 

 

This ratio is not affected by your ethnic background. Simply measure your waist circumference (as described above) and your height in cm (or in inches if you prefer) and divide the value for waist by the value for height: 

 

For example, if your waist circumference is 91cm and you are 175cm tall, your waist to height ratio would be 91 ÷ 175 = 0.52.

If that value is greater than 0.55 then you have an increased risk of developing high blood pressure, pre-diabetes, type 2 diabetes, etc…

 

Just because you have gained weight over the festive season doesn’t automatically mean you have gained fat. If you have also had an active vacation, you may have gained some muscle as well. Bioimpedance analysers, waist circumference and/or waist : height ratio are useful tools to determine if you have gained abdominal fat. If you have, you may wish to reduce your energy intake (kilojoules/calories) and at least maintain your physical activity levels to help reduce it (abdominal fat) without adversely affecting your overall body composition. 

 

Weight gain does not automatically mean fat gain.