“I’m overweight. It’s my hormones, you know.” So spoke a patient about 50 years ago. In those days we ate home-grown, nutritious, fresh food devoid of additives and contaminants. Obesity occurred infrequently, attributable to bad eating. Then the only known hormonal cause – low thyroid – was even rarer. So this patient’s comment was prophetic because, years later, other hormonal and chemical causes (sometimes existing alone or, confusingly, co-existing with bad eating) appeared, presenting themselves as a failure of weight drop.

In the 1960s, eating habits changed dramatically. Many countries decided homegrown fresh (“organic”) food was too expensive to produce and distribute, so the cheaper option of bulk chemical manipulation (processing) of food for storage and eventual distribution was started. However, certain problems appeared later, the first being an epidemic of obesity. This processed food contained more carbohydrate than the homegrown food so the population had changed from a mixed protein and carbohydrate way of eating to eating chiefly carbohydrate. The extra sugar in the carbohydrate was converted by extra insulin into fat accounting for this obesity.

Many additives have been inserted to replace the missing nutrients (vitamins, anti-oxidants, minerals), texture, colour and taste destroyed by the processing. Three of these have been used in many foods. These are: high fructose corn syrup, which is used as a high carbohydrate sweetener in soft drinks, dressings, ketchups, canned fruit and protein bars; wheat and soy derivatives in pasta, pizza and bread, bagels, biscuits, cakes and doughnuts. Incredibly, these high carbohydrate crop-based foods with these high carbohydrate additives represent 67 per cent of total calorie input in those who regularly eat such items to the exclusion of other foods. So these additives add to the obesity problem.

Another ubiquitous additive is transfat (for example, lard), which is synthetic and consists of chemically “twisted” fat molecules. Because it can be stored in solid blocks, unlike natural animal fats and vegetable oils, it is used in the processing of various carbo­hydrate foods (cakes, biscuits and pastry) and as cooking oil by some fast food outlets.Transfat generates fat causing obesity.

Bulk food processing requires bulk farming using herbicides and pesticides in crops and growth hormone in cattle to enhance production. Unfortunately, these contaminants remain in the food and behave as uncontrollable oestrogens causing obesity.

Oestrogen dominance is a recently identified condition where there is an upset pro­gesterone-oestrogen balance (the progesterone is too low and the oestrogen is too high or dominant), depressing the thyroid sensors in the cells causing obesity and many other conditions. Often, this is due to a failure in women to shed an egg which lowers progesterone production, for example at the menopause and with premenstrual tension. Non-identical hormones compared with those of the body (say, HRT, contraceptive hormones), previous pelvic surgery, stress and food contaminants can have a similar effect. Lingering oestrogen dominance responds to giving progesterone identical to that of the body.

The presence of abdominal fat, compared with elsewhere, whatever the cause, has medical significance because it secretes hormones generating more fat and obesity, cholesterol abnormalities, oestrogen dominance risking cancer, heart attack, stroke, high blood pressure and diabetes mellitus type 2.

Treatment lies in the recognition and elimination of the above causes of obesity. Also man, originally a protein-only eater, with meat shredding canine teeth and protein digesting enzymes, has not fully evolved into eating solely carbohydrates from crops and/or vegetables because the body cannot cope with this extra carbohydrate load. So the goal is to return to eating a regular three meals of organic fresh food as in the pre-1960s, thus bypassing the adverse effects of processed food.

Eating more protein, such as organic chicken, fish, free range eggs and occasional meat, and less processed carbohydrate, will keep down the weight and lead to better health because the side effects of protein are minimal compared to those of carbohydrates.

Finally, regular daily exercise (say, a 30-minute walk) stimulates the metabolism and destresses the brain, both reducing weight.

“Organic” may be 30 per cent dearer but one’s lifespan will be more than 30 per cent longer!

Dr Corney is a medical practitioner with an interest in obesity