Powering up fat burners

Last week I explained how the fat hormones leptin and ghrelin work to alert the body to hunger and starvation, thereby creating a system that needs to be understood in relation to people who are unable to lose weight.

This week we will look in more depth at the role of ghrelin. It is leptin’s opposite number and is produced in the cells lining the stomach. Levels of this hormone increase before meals and decrease after meals.

Ghrelin affects the receptor in the pituitary gland, where it stimulates the release of growth hormone by acting directly on the pituitary. It also affects various parts of the nervous system within the hypothalamus which are involved in appetite control.

It appears to be centrally involved in the regulation of energy in the body. In fact, the higher the levels of ghrelin, the hungrier we feel, so ghrelin levels peak before meals and drop after we eat.

Ghrelin was only discovered in the 1990s, so its physiological role is still not clearly understood. One study with rats produced stimulated feeding behaviour and increased weight gain after injecting large amounts into the animals. (Nature, 2001).

More importantly, a recent study with humans to assess the volume of food eaten after injecting ghrelin, in comparison with saline, was carried out. After being injected with ghrelin, the healthy volunteers were asked to select food from a buffet.

The experiment was repeated with an injection of saline solution. The results showed that the volunteers consumed more food after being given ghrelin and scored higher on appetite tests. (J. Clin. Endocrinol. Metab., 2001).

Other observations by scientists noted far lower levels of ghrelin in obese people than in those of normal weight, and a link to circadian rhythms (which are faulty in obese people). Chronic sleep deprivation increases the production of ghrelin and therefore stimulates appetite.

It is worth mentioning at this point the role sleep deprivation seems to play in weight increase. As a society, we are not only fatter than ever but we are also getting far less sleep.

The percentage of young adults who get eight hours’ sleep per night has been cut nearly in half from 40.9 per cent in 1960 to 23.5 per cent in 2002 in the US. Further evidence has shown that not getting enough sleep affects blood levels of both leptin and ghrelin as well as hunger and appetite levels (Ann. Intern. Med., 2004).

A study in Canada showed that the less sleep obtained every night, the higher the fat indices and the lower the levels of leptin. Those who reported getting seven to eight hours sleep had significantly higher levels of leptin and lower fat indices than those who had only managed to sleep five to six hours.

The researchers concluded that short-sleep durations resulted in an increased risk of the individual being overweight because of lower leptin levels. In addition, there may be an optimal number of sleeping hours at which body weight is regulated and maintained. This suggests that getting an optimal amount of sleep does more than keep you alert; it also helps you regulate your weight. (Obesity, 2007).

Various studies have looked at people possibly having leptin resistance, similar to insulin resistance in type 2 diabetes. Further studies have included taking leptin supplements which, in many cases, have shown not to work.

However, I have found a number of lifestyle choices which should ‘power up’ the fat burners.

Eat a highly varied, fresh, organic diet including colourful fruits, vegetables and herbs.

Try to eat nine or 10 fruit and vegetables per day rather than the recommended five.

Vegetable choices that specifically help fat regulators are broccoli, cabbage, carrots, leek, onions, spring onions, garlic, asparagus, bell peppers, spinach and tomatoes.

Fruit choices include bananas, apples, blueberries, cherries, oranges, grapefruit and pomegranates.

Some of the best herbs for fat burning are ginger, ginseng, cinnamon, bilberry, chamomile, green tea, peppermint, turmeric, aloe vera and Echinacea.

Pepper your diet with fresh, uncooked, unsalted nuts: walnuts, sesame seeds, almonds and linseeds. Ensure you have an adequate intake of omega-3 essential fatty acids: salmon, tuna and walnuts.

Take regular ‘sweat-producing’ exercise: aerobics helps increase leptin production.

Look at grains with a lower GI such as pasta, brown rice, quinoa, millet, oats and barley.

Cut out refined sugar. Control your carbohydrate intake and avoid all processed foods, such as white bread, potatoes, white rice, pastries, cakes and high GI foods, including beer.

Eat three good meals a day, don’t eat late at night, include protein in your breakfast meal, get seven to eight hours’ sleep each night and drink plenty of water, blueberry, cherry, pomegranate and vegetable juices.

Ultimately, the interrelationship between leptin and ghrelin, insulin manufacture and other hormone regulation in the body is highly complex, suggesting that weight gain and loss are far more complicated than simply a matter of counting calories or energy ingested, or taking a pill to lose weight.

The best approach, as always, is the holistic one – to treat the body as a single, interrelated whole and to provide it with the best fuel, the best workout and the best rest.

Under these conditions, weight normalises naturally.

kathryn@maltanet.net