Just because you're slim on the outside doesn't mean you aren't storing dangerous levels of fat on the inside...

Any products in this article have been selected editorially however if you buy something we mention, we may earn commission

We live in a world that is heavily dictated by the constant desire to be thin. A week barely goes by without some form of weight related scandal hitting the headlines -  a new extreme diet craze, clothing shops promoting stick-thin mannequins, or even celebrities editing their images to give themselves an infamous ‘ thigh gap ’. The presence of protruding bones on the body is so a la mode right now.

However, not only has this constant preoccupation with being skinny damaged our self-image, but also our ability to recognise the more serious health problems that could be taking place under the surface. For instance, place an overweight and a slim person next to each other and it would be easy to assume that the larger person was more at risk of obesity-related health problems - however, this is not necessarily the case. While the slimmer person may be carrying less fat comparatively, what they are storing has the potential to be just as, if not more dangerous - and this, is the skinny fat phenomenon.

What is skinny fat syndrome?

Skinny Fat Syndrome (medically termed as 'metabolically obese normal weight' - MONW) was first recognised back in 1981 when it was discovered that individuals exist who are not obese on the basis of height and weight, but who, like people with overt obesity, are hyperinsulinemic, insulin-resistant, and predisposed to type 2 diabetes, hypertriglyceridemia, and premature coronary heart disease.

This is because while their waistlines may appear trim, they have large amount of visceral fat (fat around the organs in the abdominal cavity) rather than subcutaneous (under the skin). Nutritional Therapist and Metabolic Weight-Loss Coach, Helen Williams  explains, “Visceral fat is far more metabolically damaging and an independent predictor of impaired glucose tolerance, insulin sensitivity, and dyslipidaemia. So, even if you are skinny and have a low BMI, high visceral fat puts you at a much higher risk of type 2 diabetes and cardiovascular disease. Worse still - if a skinny fat person already has type 2 diabetes, they are twice as likely to die than a type 2 diabetic who is overweight."

MORE GLOSS: 10 wholesome foods to consume in moderation

Having this condition is far more common than you’d think. A recent study carried out by Imperial College London estimated that up to 40 per cent of the UK population are currently carrying dangerous levels of internal fat, even in organs such as the liver, heart and pancreas. While a study conducted throughout America during 2012 showed that a startling one in four ‘skinny people’ were found to have pre-diabetes and were classed as metabolically obese.

The problem however, lies in the fact that unlike the visible signs of those overweight, MONW can often go undetected for years as people live falsely reassured by their own low body weight. “People shouldn’t think they are healthy just because they look thin,” warns Professor Jimmy Bell, from the Medical Research Council’s Clinical Sciences Centre at Imperial College. “Exercise, rather than dieting, is the way to burn off internal fat,” he adds.

Know the signs

So then, how are we to know when it’s lurking? We asked Helen Williams  to help us sniff out the symptoms of what MONW can look like.

These people may be;

  • Skinny but not fit and have central fat deposition - meaning their arms and legs are skinny but they tend to accumulate fat around the middle
  • They may not have healthy eating habits - eat very few vegetables and lots of processed foods including bread, pasta and sugar laden fizzy drinks, but still don’t put on an ounce
  • Do a lot of cardio type exercise and no weight bearing exercise
  • Have weak muscle tone
  • Have high fasting/post prandial glucose levels
  • Show signs of poor blood sugar control: including energy crashes (often in the afternoon), become sleepy after meals, experience mood swings and irritability, as well as signs of hypoglycaemia such as dizziness, fatigue and sweating when meals are missed or skipped

If you’re looking for something a little more concrete, it’s also possible to undergo a number of tests to look for the signs of being MONW. Helen advises that the following are standard tests that can be done with your GP:

  • Fasting glucose
  • Triglycerides
  • Cholesterol
  • Blood pressure
  • A glucose tolerance test can also be done which measures glucose and insulin levels whilst fasting and one hour and two hours after drinking a glucose solution

If you’d prefer to self-test it’s also possible to measure your blood sugar levels from the comfort of your own home.

“Getting a blood glucose monitor and taking your own blood sugar readings may be helpful,” says Helen. “Initially I recommend taking your blood glucose readings first thing in the morning (after fasting for 12 hours) or just before lunch, dinner and bedtime. Do this for two days. Blood sugar levels should be under 5 mmol/L at all times. More than one hour after eating your blood sugar should be less than 8 mmol/L, after two hours is should be less than 7 and after three hours it should be back to baseline. The goal is to make sure your blood sugar doesn't rise higher than 8 an hour after a meal and consistently drops to return to baseline after 3 hours.”

How to treat it

If for any reason you do find yourself experiencing any of the above symptoms or coming up positive for the aforementioned tests, don’t panic, as there are a number of measures that can be taken to help reduce the risk of MONW developing into something more sinister.

1. Spring clean your diet

“The aim is to balance blood sugar,” says Helen. “We advocate a paleo/primal template at Surrey Nutrition . Base meals on good sources of protein (lean meat, fish, poultry, eggs, nuts and seeds) and healthy fats  (coconut oil, olive oil,  avocados,) with plenty of vegetables and some fruit (berries preferably).

"Start the day with a protein based breakfast if you can. Stick to starchy carb choices including sweet potatoes, squashes and root veg such as parsnips, swede, beetroot, celeriac. Include omega 3 rich foods, such as oily fish, and avoid refined processed industrial seed oils (such as corn, sunflower, etc). Avoid cereal grains, processed/refined foods and sugar. Cut out the fizzy drinks (including diet drinks, artificial sweeteners can be just a damaging to the metabolism) and fruit juices, while also cutting back on alcohol.”

MORE GLOSS: The paleo diet: does the caveman lifestyle work?

2. Manage your stress

“When dealing with stress, the body produces higher levels of the hormone cortisol, which has a number of roles including raising the body’s blood sugar. This was great in our evolutionary past when you were dealing with a threat as the response was designed to give you the energy to fight or flee for your life, and only for short bursts. The threat was then over and levels returned to normal. However, in modern day we tend to go from one stressor to another leading to chronic stress and chronic high levels of cortisol - and thus high blood sugar levels.”

MORE GLOSS: 10 reasons you’re not losing belly fat

3. Sleep, sleep, sleep

“Aim for seven to eight hours of sleep a night and try to be in bed by 10.30pm,” says Helen. “Sleep deprivation has been shown to alter metabolism and increase cravings for carbs and sugar the next day.”

4. Build up your muscle

“Focus on weight training, which builds muscle and avoid too much cardio,” says Helen. "Balance is the key to a truly healthy body.”