Alarmingly the House of Commons Health Committee Report on Obesity estimated the economic cost to the nation of people being overweight and obese to be £6.6 – £7.4 billion. At a time where our economic future looks bleak we need to realise that it is no longer acceptable to let ourselves become overweight or obese. Nor is it acceptable to put the responsibility of our health care on to others such as the government and the National Health Service (NHS). We need to take responsibility for the decisions we make in our lives including the decisions that affect our health. Of course there are genetic and environmental factors that contribute to our body shape and our health – but no one gets obese just from having “bad” genes. People only get overweight or obese from what they chose to eat on a daily basis and from lack of exercise.
What’s wrong with being a little bit fat?
Fat is not just an unsightly inert substance that sits on your love handles or muffin top. It does not just serve as a reservoir of energy to be called upon when needed for energy. Fat is metabolic tissue that can cause all manner of things to happen in your body. Fat cells release the hormone leptin that serves as a signal for energy sufficiency. Leptin levels decline with calorie restriction and weight loss and rise above normal levels with weight gain and obesity. Obesity can lead to leptin resistance, much like insulin resistance whereby leptin can no longer tell the brain that we are full. This may lead to overeating. Leptin also interacts with other hormones such as stress and thyroid hormones, it modulates the immune system and aids bone formation. Disrupted leptin levels through obesity can affect how these hormones work, affect the immune system and alter bone formation.
Fat cells become infiltrated with high levels of immune cells that release inflammatory chemicals disrupting the uptake of sugar and burning of fat in liver cells contributing to insulin resistance, the onset of type 2 diabetes and narrowing arteries. Fat cells release chemicals that clot your blood, increase your blood pressure and convert inactive stress hormones into active stress hormones and contribute to conditions such as hypertension, stroke, cardiovascular disease and PCOS.
Fat cells also convert male hormones to female hormones. This may be a good thing for post-menopausal women as this provides a source of oestrogen, but this is not good for pre-menopausal women who presumably have normal oestrogen levels, nor is it good for men, making them more feminine. There are also links between excess oestrogen and conditions such as fibroids, endometriosis, breast and ovarian cancer.
How do you know if you are at risk?
There are several ways to ascertain your weight and body composition (fat mass compared to muscle tissue) and whether you are at risk from being overweight and at risk from the associated health conditions. These same measurements can be employed to monitor your progress on a weight loss programme.
Standing on the scales is the first port of call for most people. Although measuring your weight is good practice you need to remember the scales only tell you your gravitational attraction to the earth in stones, pounds or kilos, they do not tell you anything about your body composition or about your regional fat distribution. To get a true body weight and chart your weight loss only weigh yourself once a week, on the same day, at the same time, on the same pair of scales after emptying your bladder and bowels and whilst naked. Deviating from this advice could give you false and highly variable readings.
Body mass index (BMI) is another measurement tool used to determine whether you are under, over or of normal weight. BMI, a calculation of your bodyweight in kilos divided by height in meters squared, is generally a reliable system, but it is not without criticism, for example a male with a lot of muscle mass may actually be of “normal” weight and body fat for his height but is classified as being overweight, whereas someone who has very little muscle mass but some additional fat (thus being technically termed a skinny fat) may show up in the normal band. Additionally, BMI does not tell you anything about other important markers for health and disease such as waist circumference, body fat percentage or regional body fat storage.
Waist circumference (WC) and waist to hip ratios (WHR) are two good measures employed by health professionals as a simple and effective tool to identify obesity and disease risk. Research has demonstrated that men with a normal BMI that had a 40 inch waist were twice as likely to die as men with a 34 inch waist and women with a normal BMI that had a 35 inch waist were 79% more likely to die than women with a 29 inch waist. Waist circumference can be measured with a standard tape measure and should be measured around (what should be) the narrowest point of the waist between the rib cage and hips. Clearly a lower score is better.
Numerous studies have demonstrated the metabolic complications and disease risk of having a high waist to hip ratio (i.e. a greater measurement in inches or centimetres at what should be the narrowest point around the waist compared to the widest point of the hips). The true healthy waist to hip ratio may vary a little depending on which studies you read, but could be classified as less than 0.85 in women and less than 1 in men (i.e. women should have a much narrower waist than hips, and men should have a slightly narrower waist than hips). Again this is easily measured with a tape measure.
Knowing your body fat percentage is also important to assess your risk of disease and chart your weight loss progress, clearly the more overweight or obese you are the more body fat you will have. But “thin” people can also have excess body fat. Normal levels of body fat differ depending on which sources you depend on but the World Health Organization and National Institutes of Health recommendations are:
Women
| Age | Under fat | Healthy Range | Overweight | Obese |
| 20-40 yrs | Under 21% | 21-33% | 33-39% | Over 39% |
| 41-60 yrs | Under 23% | 23-35% | 35-40% | Over 40% |
| 61-79 yrs | Under 24% | 24-36% | 36-42% | Over 42% |
Men
| Age | Under fat | Healthy Range | Overweight | Obese |
| 20-40 yrs | Under 8% | 8-19% | 19-25% | Over 25% |
| 41-60 yrs | Under 11% | 11-22% | 22-27% | Over 27% |
| 61-79 yrs | Under 13% | 13-25% | 25-30% | Over 30% |
I would suggest from my own personal data collected over the last 4 years (in athletes and the general population) that the “under fat” and lower “healthy range” from the charts above are actually the healthy ranges and the upper “healthy range” is actually bordering on being overweight.
Stay tuned for part 2…