PAMF Health Blog

Be Well, Be Well Informed

Health Risks of ‘Skinny Fat’

Posted on Dec 4, 2012


A significant number of people are in fact, ‘fatter’ than they think. When I say someone is fat, I don’t mean it in a derogatory way. I define ‘fat’ as someone who carries excess adipose tissue (scientific term for fat) that may be visible or invisible, but is enough to cause metabolic changes that increase the risk of developing conditions such as heart disease and diabetes. Individuals who do not appear fat on the outside, but show internal biological signs of carrying dangerous amounts of excess fat tissue, are casually termed ‘skinny fat.’ The more recently used medical acronym for skinny fat is MONW (Metabolically Obese Normal Weight). Basically, this refers to having too much fat and too little muscle.

Dangers of being ‘skinny fat’

We’ll talk about how to determine if you are ‘skinny fat’ in a moment. First, I want you to know how risky this condition is. A study in the Journal of the American Medical Association (JAMA) showed that 1 in 4 skinny people have prediabetes and are ‘metabolically obese.’ What was really a surprise is that the study found if you are ‘skinny fat’ at the time you are diagnosed with diabetes, then your risk of death is double that of someone who is an overweight diabetic. When it comes to being fat, you cannot judge a book by its cover and don’t rely on the opinions of family members or others around you.

Are you ‘skinny fat?’

So, how can you tell if you are ‘skinny fat?’  Here are a few clues:

1)  Body measurements: Rely on waist circumference and waist-to-hip ratios to guide you.

2)  Cholesterol profile: If your cholesterol in particular, shows high triglycerides, especially in combination with a low HDL (good cholesterol), then this is a sign of skinny fatness.

3)  Blood sugar: If your blood sugar is consistently in the pre-diabetic range, or you are diabetic with inadequately controlled blood sugars, then you likely have some excess body fat.

4)  Liver blood test: Many South Asians have an elevated liver inflammation test known as the AST or the ALT. This is an early indicator of excess fat in the liver which can cause inflammation.

If these tests are abnormal, then the fatty liver is confirmed by an ultrasound. I recommend you get liver function tests done if you have any of the other signs on this list.

What to do if you are ‘skinny fat?’

The most important hormone in your body that determines fat storage in your body is insulin, and the most significant cause of insulin release is carbohydrates in your diet. Ironically, fat does not cause insulin to go up. Foods that are carbohydrate-rich will make you fatter than foods that have excess fat. Many of my patients who have the most excess body fat are South Asian vegetarians who consume no meat or excess fat in their diet, but instead consume lots of carbohydrates in the form of rice, breads, lentils, beans and starchy vegetables like potatoes. Crispy snacks and sweets also worsen the problem. So, to lower that extra fat, lower your carbs!

The next step is to make sure you get your body moving.  As a first step, take more steps. Get a pedometer and aim for an initial goal of more than 5,000 steps daily and then ultimately, at least 8-10,000 steps daily.  On top of this, try to get in at least 2-3 sessions of cardio and 2-3 sessions of weights in per week. You can combine your cardio and weight sessions into one workout by doing interval or circuit training where you perform a series of exercises consecutively to maintain an elevated heart rate. This will simultaneously allow you to increase endurance and strength. You can check out my short video on cross training for examples.

If you do show signs of being ‘skinny fat,’ be sure to work closely with your doctor to reduce your risks. You may also benefit from a referral to see a PAMF nutritionist or if you are South Asian – to a PAMF South Asian Health expert.

Ronesh (Ron) Sinha, M.D.

This blog post is contributed by Ronesh (Ron) Sinha, M.D., Palo Alto Medical Foundation Internal Medicine. Dr. Sinha works closely with the South Asian community to help reduce heart disease and diabetes risk, and provides corporate health lectures to promote wellness in the workplace. Dr. Sinha holds clinical faculty positions at UCLA; Stanford University School of Medicine; and the UCSF School of Medicine. He teaches Stanford and UCSF medical students.