Harness hormones to lose weight

Hormones play a major role in firing up your metabolism and help you hit your weight-loss goals, but only if you know how to handle them correctly.

'It's just my hormones' is a common response from many who struggle to lose weight. But a growing body of research suggests that there really is something to that old excuse. Men looking to shift a few pounds could do a lot worse than learn how their hunger hormones work.

"We're discovering that hormones such as leptin, ghrelin and testosterone often call the shots as to when you eat and when you don't," explains Dr Scott Isaacs, endocrinologist and author of Hormonal Balance.

How these hormones work
Leptin, is made within the body's fat cells. When leptin levels reach a threshold, a signal tells the brain that there's enough 'energy' in the cells for your body to function normally — this then turns down our hunger pangs.

When we're dieting and exercising the draining of fat from body cells sets off leptin alarm bells. These tell the brain that we're insufficiently stocked for energy and should eat more. "Eating more fruit, fibre and foods high in zinc may help your body balance its leptin levels without impacting on your waistline," suggests Dr Scott Isaacs.

"In extreme cases, overweight people can develop a 'leptin resistance' whereby the messages from the hormones get scrambled and despite the leptin levels reading 'full' they still feel hungry."

Sleep is essential
But no matter how well you eat, a lack of quality sleep can lead to a dip in leptin levels and scupper weight-loss attempts. "Aim to get seven to eight hours' sleep a night," says Dr Isaacs. Researchers at the University of Chicago, looking into links between sleep and hunger hormones, found that when they limited 12 male volunteers to just four hours of sleep for two consecutive nights their leptin score dropped by an average of 18 per cent.

In the same US study, the research team noted that the sleep-starved men also recorded a surge in the hormone ghrelin — on average up by 28 per cent. While leptin works to regulate your hunger levels, ghrelin's purpose is to tell the hypothalamus in the brain that you need to eat more.

Ghrelin is produced in excessive amounts by cells in your stomach lining when the gut is empty. "It acts on the brain to make food more appealing," explains Dr Alain Dagher of the Montreal Neurological Institute, McGill University, Montreal. Dagher's team discovered that after test subjects were given an infusion of ghrelin they rated pictures of foodstuffs as being much more appealing than they had before. "Ghrelin is a hormone that influences memory too — making you think you're hungry when you're really not."

"Be sure to eat a breakfast that's filling then eat little and often through the day," suggests Dr Isaacs. By feeding ghrelin and not skipping meals you can keep it in check.

Stress — both emotional and physical — can spike levels of hormones that in turn can make us fat. When we're stressed the brain flicks an internal switch to produce increased levels of two 'fight or flight' hormones — cortisol and epinephrine. These were useful chemical triggers for primitive man, helping him to outrun 'caveman-era' stressors such as the sabre-tooth tiger.

Modern-day stresses
But when it comes to modern-day causes of anxiety, such as sabre-tooth work deadlines or mammoth family ructions, a rush of excess cortisol can lead to a build-up of visceral fat in your stomach.

Research from Ohio State University, in the US, indicates that by raising your exercise levels to an a hour a time — three times a week — to a point where you're working at 75-80 per cent of your maximum heart rate you'll reduce stress levels and put that cortisol overload to good use.

Exercise is key to boosting another hormone that will affect your diet too. Testosterone, at the right balance, helps men develop muscle, maintain energy levels and keep fat at bay. If you're overweight or obese you're twice as likely to have low testosterone too.

"Studies show that resistance exercise — such as weight training — can help raise levels of this hormone, though it goes through a natural decline as we age," says Dr Isaacs. Following a winning football team may also play a part as researchers discovered that a man's testosterone level can surge up when watching his favourite team, but also drop by up to 20 per cent when his teams loses.

A diet that's rich in monounsaturated oil — found in avocados and oily fish — also helps preserve testosterone according to data published in the Journal of Applied Physiology.

Those oily fish will also provide a source of iodine, which in turn boosts the body's production of thyroxine (T4). "It's a hormone that raises your metabolic rate, energises your body and gives you the tools required to go the extra mile," says Dr Andy Grossman, endocrinologist at Barts Hospital, London. "If your thyroid gland doesn't make enough thyroxine, it causes many of the body's functions to slow down."

If you can follow the experts' advice and maintain your hormonal balance then the next time you get a compliment on how good you're looking then you can blame your hormones.