- In many countries, including the UK, social services are keen to blame parents when children are too heavy or too thin. I think it is important for people who work in social or health services to know that children may be underweight because of genetic factors. It is easy and inexpensive to analyse genetics these days. When you have the answer, you don't take the child to a psychologist, you don't try to increase their appetite; instead you take them to a dietician and try to increase the quality of their food – they won't eat more but if you can increase the density of calories you can increase the weight. We do the same for people who have cancer or old people.
So on to 'Experts targeting obesity raise hope of drugs to stop us feeling hungry'. Experts eh? You've go to love them. The experts who are targetting obesity in this article are probably economists and accountants, but I digress (when I should be ranting):
- "Humans evolved at times when food was scarce and when we faced starvation all the time," says Professor Waljit Dhillo, at Imperial College, London. "Those who survived were the ones who were able to eat most food and could sustain themselves through periods of famine. They passed on the genes for that ability to future generations. It was useful then, when times were hard, and it ensured our species survived famines.
- During the 2000 fuel strike, Sainsbury’s chief executive wrote to the prime minister to warn that food supplies would run out “in days rather than weeks”. Supermarkets rationed bread, sugar and milk.
- "There appears to be many chemicals involved in sending chemical messengers from the gut to the brain," added Dhillo. "The trick is to find the most important ones."
A region of the brain called the hypothalamus plays a critical role in dealing with digestion and controls chemical messengers that pass between the brain and the gut. Researchers have isolated two of these messengers, chemicals released by cells in the intestine which are closely linked to appetite suppression. One is known as Glucagon-like peptide-1, or GLP-1, and the second is known as Peptide YY, or PYY. "We recently carried out experiments on adults who had fasted for 12 hours," added Dhillo. "We monitored their brain activity and found, when we showed them pictures of food, particular areas of their brains lit up in our scanners. It was a measure of how interested they were in food.
"Then we gave them an infusion of GLP-1 and PYY and again showed them the pictures of food. Their brains did not light up nearly so much. In other words, they were less stimulated by the sight of food. They had lost their hunger. Essentially, PYY and GLP-1 suppressed their appetites."
Both hormones break down easily in the gut and so their direct use as a drug is limited. However, chemically altered versions of GLP1 – known as exenatide and liraglutide – are already used as a treatment for diabetes because they cause weight loss and also boost insulin secretion in the body. "The trouble with these drug hormones is that they are short-acting," added Dhillo. "Most break down quickly. So pharmaceutical companies are developing analogue versions which have the same effect but last for longer in the body. Some could be administered once a week.
"The future will be to develop a multi-hormone injection that is given in a low dose, so that you do not get any side-effects, and will be long-acting enough so that you need only take it once a day or once a week.
You always have to ask yourself with these 'cures' whether they are treating a symptom or the underlying cause. Follow the money and don't expect to 'get well'.