What is “Skinny Fat”?

Skinny fat is a not-nice-term used to describe those with a normal weight, but who also have a high body fat percentage. While it may not be a medical term, it is a real medical issue and linked to poor metabolic health.

Metabolic dysfunction is often associated with obesity, but obese persons can be metabolically healthy. On the flip side, people with a “healthy” BMI can have poor metabolic health. 

What is Skinny Fat?

“Skinny-fat” is medically known as “metabolically obese normal weight”, or MONW. It refers to people who have a “normal” BMI, but have high levels of body fat and multiple cardio-metabolic disorders that are associated with an increased risk of cardiovascular disease and all-cause mortality.¹

BMI neither discriminates between fat and muscle nor considers body fat distribution.  People who are “skinny fat” fall into the low to normal BMI range, but actually have relatively higher body fat, less fat-free mass, and a tendency for carrying more abdominal fat. It is also linked to to people who don’t do much physical activity and have low cardiorespiratory fitness.²³⁴

Being skinny fat is associated with poor metabolic health, which means having cardio-metabolic disorders such as inflammation, insulin resistance, low good cholesterol (HDL), and high blood pressure, triglycerides (similar to bad cholesterol), and blood sugar.⁵

With so much emphasis on weight, it’s easy to conflate weight with body fat and health. While all of these are linked, but still separate. Furthermore, BMI and body weight are not markers of metabolic health. Research suggest that up to 45% of “normal” weight people may be skinny fat.⁶

How “Skinny Fat” Affects Health

People who are “skinny fat” are at risk of suffering with diabetes, metabolic syndrome, and cardiovascular disease.⁷

Here’s how being skinny fat causes health issues:

Visceral Fat. Skinny fat people tend to carry more abdominal (visceral) fat – the type of fat deep inside your belly, around your organs. Visceral fat, is metabolically very active, sending out chemical signals that in time lead to insulin resistance, diabetes and heart disease.

Low muscle. People who are “skinny fat” also tend to have less muscle mass. Research shows that higher muscle mass is linked to a lower risk of risk of death and heart disease, irrespective of levels of body fat.⁸ In other words higher levels of muscle mass help reduce the risk of mortality.⁹

Inactivity. The effects of body weight and exercise on metabolic health and premature death are separate and additive. That means having a normal BMI does not cancel out the increased risk associated with inactivity and poor diet.¹⁰¹¹

The deception of normal BMI and poor metabolic health is particularly perilous, as it easily goes undetected and undiagnosed by doctors. So the elevated risk to disease goes unchecked and the opportunity for preventing diabetes, heart disease, and other chronic conditions is missed. By the time people who are skinny fat seek out their health professional, they are more likely to be at the advanced stages cardio-metabolic disease and treatment is more difficult and complicated.

What to Do If You’re Skinny Fat

If think you’re skinny fat, get body composition analysis. You should be able to get this done with skinfold calipers or by other methods at any gym and fitness club. Also, try your local college campus, which should also be cheaper. Alternatively, you can buy body fat analysis scales or use this body fat calculator, though they are less precise.

People who are skinny fat should make weight training part of their workout routine, as well as cardio. Use cardio to burn fat, while helping you gain muscle by exercising at high resistance or incline, if you can. For example, if you are running outdoors or on treadmill run at a higher incline (compensate by going slower) to build muscle or try HIIT.

If you are using the cross-trainer or elliptical trainer set it at a higher resistance and go slower than you would normally. You can still burn the same amount of calories at high resistance/ incline as you would with low resistance. However, importantly you are exerting a different effect on muscle.

Try to follow a balanced diet of veggies, fruit, healthy fats, and lean meat. It’s understandably easier for people who are skinny fat to make poorer food choices, because they have a normal BMI and can’t see the effects physically like most other people.

How to Get Started

• Body composition analysis.
• Strength training 3x per week.
• Cardio workouts 3x or more per week.
• Incorporate HIIT training, to boost muscle mass.
• Try weight training followed by a shorter cardio session for muscle building and fat burning.
• Correct poor dietary habits.
• Reduce sugary or high-calorie drinks.
• Keep to your daily calorie requirements. Lower your calorie intake moderately if necessary. Avoid a very low calorie diet, it may further reduce muscle mass.
• Eat protein with every meal. Protein is the building block of muscle and is vital for tissue repair.
• Eat a small protein and carbohydrate rich snack 30 minutes before and 30 minutes after your workouts.