You watch what you eat and exercise, so why can't you lose weight? Many scientists believe that hormonal imbalance could be to blame for your weight gain and inability to shed the pounds. Here are five hormones associated with weight gain – and how you can make them work for you.
See also: Best low-calorie foods to fill you up
See also: Fast ways to a flat stomach1. Insulin
How much insulin you produce affects how much glucose your body uses from carbohydrates, and how much is stored away as fat.
When you eat sugar or starch (found in sweets, bread, potatoes, rice or pasta), the starch and sugars are digested down into glucose, which is then absorbed into the bloodstream, causing your blood-sugar levels to rise.
In response, the pancreas produces a hormone called insulin which is released into the bloodstream. When insulin is working well it sends most of the glucose to the cells in your muscles to use as fuel, some to your liver, and little or none to your fat stores.
Several things can mess with the proper functioning of your insulin levels – and potentially make you insulin resistant (a condition in which cells become less responsive to the hormone, which can lead to diabetes). When that happens, insulin begins to send less glucose to the liver and muscles, raising the concentration of glucose in your bloodstream and ultimately storing the glucose as fat.
You can also control the amount of insulin your body produces by swapping processed, refined carbs like white pasta and bread for whole-grain versions, which contain fibre to slow the absorption of sugar into the bloodstream. As well as keeping your insulin levels steady, fibre has the advantage of keeping you feeling fuller for longer.
Eating little and often (choosing protein rather than carb-based meals) is another way to maintain consistent levels of glucose and insulin throughout the day.
Ghrelin is the hunger hormone – go without eating, and your ghrelin levels rise and make you hungry, making it hard to resist food. Ghrelin is highest in the morning after you've gone without eating all night, so you really need to eat first thing to keep it in check. When you're mildly hungry it's easy to choose a healthy option – wait until you're ravenous and you're more likely to grab a fattening snack.
Make it work for you: Eating a high protein meal lowers ghrelin levels significantly more than meals high in fat and carbohydrates, according to a study published in the journal Clinical Science. For this reason, it's a good idea to opt for a protein-based breakfast, such as eggs. Aim to eat 20 grams of protein at every meal to help keep ghrelin levels in check.
Leptin is an appetite suppressor that tells you when to stop eating. Unfortunately, the hormone works less efficiently as we get older – so it's even more important to keep an eye on your portion sizes over the age of 50.
Make it work for you: Eating a diet rich in omega-3 fatty acids and Eicosapentaenoic acid (EPA) has been shown to stimulate the production of leptin. Aim to eat more salmon (no more than twice a week), mackerel, and sardines. Sleep deprivation lowers leptin and increases ghrelin, which makes you crave calorie-rich foods. Getting eight hours of sleep each night can help keep your hormones and appetite under control.
The more stressed you are, the more likely you are to carry excess weight around your middle. When stressed, the body releases a hormone called cortisol, which encourages excess visceral fat on the belly. At the same time, you're more likely to crave sweet and carb foods, as these release serotonin, making you feel good.
Make it work for you: Caffeine encourages your adrenal glands to release cortisol, so avoid drinking coffee when you're stressed. Drinking two and a half to three cups of coffee while under mild stress can make your cortisol levels jump by 25% and stay elevated for three hours, say researchers at the University of Oklahoma.
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