Thin Outside, Fat Inside. What does that mean?
This is something that I have to confess was quite shocking to me when I first heard about it. It relates to people that appear to be slim on the outside but still have an excess amount of visceral fat – or internal fat as opposed to subcutaneous fat, which is found just beneath the skin. Visceral fat lies around vital organs, the muscle and heart. Accumulation of visceral fat leads eventually to insulin resistance, diabetes and heart conditions;
Recently, I attended a talk given by Professor Jimmy Bell and organised by the KCL Pharmacology Society, which really changed my perspective on appearance. Professor Bell discussed many aspects of his research, which aims to the development and maintenance of Optimal Health throughout adult life.
Using Magnetic Resonance Imaging (MRI) he was able to show that people of similar age, gender, BMI and same Percent Body Fat had completely different body fat distribution.
MRI comparing two males of similar age, BMI and same Percent Body Fat. Fat shown as bright and lean tissue as dark.
He stressed that this referred to men and women that have a BMI of 25 or lower and do moderate or no exercise. To my surprise one of the TOFI examples he used, were also underweight people, such as fashion models; Whereas on the other hand, he used the example of Sumo wrestlers that have a BMI of 56 and consume up to 8,000 calories per day but exercise daily and have little visceral fat;
So is BMI adequate to determine if someone is healthy?
Body Mass Index:
|Underweight||Less than 18.5 kg/m2|
|Normal Weight||18.5 to 25 kg/m2|
|Overweight||25 to 30 kg/m2|
|Obese||30kg/m2 and above|
|Morbidly Obese||40kg/m2 and above|
Although the value for BMI is used commonly to distinguish people that are underweight, normal weight, overweight, obese and morbidly obese, Professor Bell stressed that it is not a definitive measure of health in relation to body fat particularly on the lower range of BMI.
Take Home message: Stay Active!
Whatever the type of exercise, try and complete a workout everyday!
Whether you aim to complete 12,000 steps a day, play a tennis game or just brisk walk 30 minutes a day, add exercise to your routine! Professor Bell’s activity recommendations for those not in favour of the activities mentioned above was to stand up, balance on one foot for a minute then change foot and balance again and make sure this is repeated during the day several times.
Further Reading if you are interested:
Shojaee – Moradie F., et al. Exercise training reduces fatty acid availability and improves the insulin sensitivity of glucose metabolism. Diabetologia (2007) 50: 404 -413
Thomas E.L., et al. The Missing Risk: MRI and MRS Phenotyping of Abdominal Adiposity and Ectopic Fat. Obesity Journal (2012) 20, 1: 76 – 87