The chemical messengers in your blood will help you smash your weight-loss goals. Here’s the skinny on the science…
In the weight-loss conversation, almost everyone obsesses over diet and exercise. However, the latest science shows that not only are your hormones a defining factor in how you age, they also play a crucial role in the way you put on (or lose) fat. Calories, of course, remain king. But armed with our crash course on hormones, you can expect to burn off a princely sum in your pursuit of a lean physique.
01 Leptin and Ghrelin
Blame these two if your gut grumbles an hour after you’ve eaten. Leptin, released by your fat tissues, alters your appetite in the long term by telling your brain when you have stored enough fat. Ghrelin, produced in the gut, signals to your brain that you’re hungry. If either is out of whack, cravings will strike.
Life Hack: Protein, protein, protein. Eating 30g at each meal reduces ghrelin it’s why you feel so full after a sirloin. Regularly eating protein may also lead to increased leptin sensitivity in the brain. Brian St Pierre, director of performance nutrition at Precision Nutrition, says that 30g is about a palm-sized amount.
The latest weight-loss hero on the block, this “exercise hormone” was only discovered in the past decade. Scientists believe that Irisin has the superpower of converting white fat, linked with an unhealthy metabolism, to brown fat, which is linked with effective calorie burn.
Life Hack: To make the most of this hormone, mix up your workouts. If you’re not throwing some high-intensity work your routine, it’s you started. It doesn’t even have to be plan: just seconds with a rope (or performing jumping jacks) between weight sets. Alternatively, introduce a few sprints to your usual run, or between lifting sets.
03 T3 and T4
Your thyroid is a small but mighty gland that sits beneath your Adam’s apple. Its main job is to regulate T3 and T4, two chemicals that manage your metabolic rate. (That’s how many calories you burn at rest.)
Lift Hack: Go nuts, or go fish. Your thyroid produces T3 and T4 with the help of selenium, a mineral found in large amounts in Brazil nuts, tuna and halibut. “About 200mcg per day could optimise your levels of thyroid hormones, as long as your thyroid is working well,” says Theodore Friedman, a professor of medicine at UCLA. Just three Brazil nuts or 200g of cooked tuna will deliver well over that amount.
This hormone keeps your blood sugar in check and helps your body to store fat and build muscle. Weight gain can lead to ‘insulin resistance’, which means your cells don’t respond well to it. As a result, your pancreas compensates by producing more. Over time, the combination of high insulin levels and insulin resistance can make it harder to lose weight.
Life Hack: Instead of ‘low carb’, go for ‘slow carb’ advises St Pierre. Your digestive system requires more time to process nutrient-dense carbohydrates. These foods slow down digestion and help you stabilise blood sugar and insulin levels.
You know T as the muscle building hormone, but it pulls double duty. Men with low testosterone tend to gain fat more easily, says Men’s Health nutrition adviser Mike Roussell.
Life Hack: Give it a rest. Even a single week of poor sleep can significantly lower your testosterone level, warns Roussell. One saboteur, sleep apnoea, has also been linked to low T, says Friedman. If you sleep seven to nine hours but still feel tired throughout the day, talk to your doctor, who may refer you to a sleep clinic.
Exposure to high amounts of stress produces the hormone cortisol, which can cause muscle breakdown and a redistribution of fat to your gut. “High levels at night are one of the biggest causes of weight gain, especially belly fat,” says Friedman.
Life Hack: Install a “phone bowl” in your bedroom and keep it far away from your bed. That means no mindless scrolling in bed, and therefore no more sleep lost to the smartphone abyss. Another perk: a solid night of sleep is a natural stress-reliever.
07 HGH and IGF-1
Your pituitary gland produces HGH, which stimulates the production and secretion of IGF-I by your liver. Both are growth hormones that break down fat and use the energy to strengthen your muscles.
Life Hack: Set a snack curfew. Don’t eat anything for two hours before you go to bed. Food will reduce the natural surge in growth hormones during the early hours of the night. (No, staying up later will not reduce this effect.) As an incentive, know that losing 5kg can raise your IGF-I level, says Friedman.