It’s no secret that there are many health hazards associated with being overweight or obese; high blood pressure, heart disease, and diabetes are often the worst offenders. What you might not have known is that these health hazards can also be associated with being a normal weight. It’s called being a TOFI, ‘Thin Outside, Fat Inside’, and it’s estimated to affect 13% of people with ‘normal’ BMIs (The Guardian).

You’re TOFI when you have a relatively lean body or healthy body weight, but actually harbor visceral fat around your organs instead of subcutaneous fat under the skin. Fat around your abdomen is by far the most dangerous, but fat within your abdomen is even worse. TOFI's have a higher risk of developing insulin resistance and type II diabetes than an overweight person, who is already at a higher risk than a healthy individual. They are more likely to suffer from a fatty liver and systemic inflammation and other metabolic diseases.

The danger of being TOFI is that everything looks fine. You exercise and appear to eat right. You look healthy, you look lean, you don’t have parts of you jiggling that shouldn’t, so why would you ever consider that something is wrong? In reality, you could be pre-diabetic. You could have skyrocketing levels of cholesterol. The only way to determine if you have visceral fat is through magnetic resonance imaging or CT scans; it is not something you can self-diagnose.

Notice below that these figures are very similar in size. Both are 35-year-old males with a BMI of 25, which is considered healthy. Outside of this MRI, they probably have similar figures. The person on the right has 5.86 liters of visceral fat in his abdomen compared to the person on the left, who only has 1.65 liters of visceral fat. Would the person on the right ever think he was unhealthy? Or at risk for diabetes?

Despite living an active, healthy life, you could still be in danger of the consequences of being TOFI. One of the biggest, most supported theories is the role of sugar in developing visceral fat. Meta-analyses support the idea that excess sugar consumption leads to development and worsening of metabolic syndrome (One of the main symptoms? Abdominal obesity). But you eat healthy and avoid sugar, right?

Popular ‘healthy’ dietary staples like smoothies, protein bars, and most fruit juices are loaded with sugar. There isn’t enough fiber in practically anything other than whole fruit (or juice if you do it yourself) to counterbalance the amount of sugar you’re ingesting. Sugar without fiber overloads the liver, leading to high levels of insulin production and fat storage. It’s not just the ‘healthy’ foods, but your breads, cereals, pasta sauces, and every other processed product. The average American consumes over 5-7 times the recommended daily allowance of sugar every day because it’s hidden in everything.

If your diet consists of mostly processed foods, but you look healthy, you could be at risk of having a high percentage of visceral fat. Be sure to read you food labels; you only need 6-9 grams of sugar a day if you’re an active adult, and sugar comes with many names including fructose, sucrose, corn syrup, etc. Swap out processed foods for whole foods and learn to make your own snacks instead of buying them. And if you’re truly worried about health hazards like diabetes or heart disease, go get an MRI if you’re able. Don’t let hidden sugars cause you hidden danger!