If you think that being lean automatically exempts you from obesity-related diseases, think again. Scientists have identified a condition they’ve dubbed skinny fat syndrome, which brings the same risks as abdominal obesity, in which you tend to store fat around your internal organs.
Skinny fat is visceral fat
Based on a genetic analysis of over 75,000 people, carried out by the UK’s Medical Research Council, they found that some lean people have a specific gene variant that increases their risk of developing type 2 diabetes and heart disease, despite their lower body fat. As with central obesity, this gene makes it harder for them to store fat under their skin and causes them to lay down any excess fat around their internal organs.
‘Normal’ fat (white adipose tissue, or WAT) that’s stored under the skin is not as strongly associated with health problems as the visceral fat that accumulates around your organs, or within your muscles and liver. The same applies to lean people who have ‘normal weight obesity’ or ‘skinny fat syndrome’ even if your scales show your weight is in the normal range and your BMI is considered within the healthy range for your height.
Visceral fat is metabolically active, and leaks hormones free fatty acids and inflammatory chemicals directly into the circulation. These travel directly to the liver (alongside nutrients absorbed from your diet) for processing. Within the liver, these hormones and inflammatory chemicals activate genes that increase the production of cholesterol, triglycerides and new glucose. As a result, having skinny fat syndrome changes your metabolism towards that associated with metabolic syndrome even if you don’t have the classic abdominal obesity with a large waist.
Who is at risk of skinny fat syndrome?
Small-boned, lean individuals are most commonly affected. Women are also more prone to being skinny fat than men as they naturally have less muscle and more fat. If you lose considerable amounts of weight by dieting without exercise, you’re also at risk.
The typical ‘skinny fat’ person looks slim and fit when fully clothed but when seen naked, have little muscle tone. Areas of loose skin may hang down, such as bingo wings on the upper arm, and females may have extensive areas of cellulite even though their hips and thighs are relatively slender.
This is not just a cosmetic issue, as even the small amount of invisible fat deposited in and around your muscles, liver and heart disturbs their normal function and increases levels of inflammation within your body. In short, it triggers premature ageing and the health risks associated with more obvious obesity.
Tackling skinny fat syndrome
If you think you could have skinny fat syndrome, have your body fat percentage checked professionally, or by a set of scales that use bioelectric impedance to accurately assess your body fat percentage. These are available at an incredibly cheap price from Amazon.co.uk and Amazon.com.
Then look at the following body fat percentage charts and see where your body fat percentage fits depending on your age and gender.
| Female Age | Underfat | Healthy | Overweight | Obese |
| 20 – 40 years | Less than 21% | 21% to 33% | 33% to 39% | Over 39% |
| 41- 60 years | Less than 23% | 23% to 35% | 35% to 40% | Over 40% |
| 61 – 79 years | Less than 24% | 24% to 36% | 36% to 42% | Over 42% |
| Male Age | Underfat | Healthy | Overweight | Obese |
| 20 – 40 years | Less than 8% | 8% to 19% | 19% to 25% | Over 25% |
| 41- 60 years | Less than 11% | 11% to 22% | 22% to 27% | Over 27% |
| 61 – 79 years | Less than 13% | 13% to 25% | 25% to 30% | Over 30% |
You can also calculate your body fat percentage based on your body mass index (BMI) and gender. Although not as accurate as professional calculations based on skin-fold measurements and bioelectrical tests, this will give you an idea of whether or not you could have skinny fat syndrome.
Step 1: Find your BMI
First, use this calculator to work out your Body Mass Index using either metric or imperial measures, which ever you prefer. This will give you a number which is your BMI.
Supplied by BMI Calculator USA
If you are within the healthy weight for your height, your BMI will be between 18.7 and 23.8 Kg/M2 for women, and 20 to 25 Kg/M2 for men. But despite having a healthy BMI are you skinny fat?
Step 2: Calculate your body fat percentage
According to a study published in the British Journal of Nutrition, if you are an adult, your percentage of body fat can be estimated accurately from your BMI using the following formulas.
Females
Body Fat Percentage = (1.20 x BMI) + (0.23 x Your Age) – 5.4
Males
Body Fat Percentage = (1.20 x BMI) + (0.23 x Your Age) – 16.2
Example calculation
If your BMI is 24, and your age is 30, the calculation would start off as:
1.2 x 24 = 28.8 then add 0.23 x 30 = 6.9 giving you a total of 28.8 plus 6.9 = 35.7
Then, if you’re female, deduct 5.4, and if you’re male, deduct 16.2
This would estimate your body fat percentage as 30.3% if you’re female.
This would estimate your body fat percentage as 19.5% if you’re male.
Step 3: Check the charts
Now go back to look at the table of body fat percentages above, and you’ll see that for a 30-year-old female, a body fat percentage of 30.3% is in the healthy range. For a 30-year-old male, a body fat percentage of 19.5% is within the overweight range, even though your BMI of 24 is ‘healthy’. This could mean you have skinny fat syndrome.
How to beat skinny fat
Ask your doctor for a check up to assess your blood pressure, triglyceride level, cholesterol balance and diabetes risk.
If you have too much fat and too little lean muscle, the answer is to combine a healthy eating program, to eat more protein, and to increase the amount of exercise you take to start building up lean muscle in place of that internal fat.
