Nobody likes a nag... but try telling that to the bag of fun-size Mars bars that won't stop calling your name. A craving is like a little devil, constantly encouraging you to indulge. And if you're actively trying to lose weight, it only ups the pressure. A study published in the International Journal of Obesity found that 91 per cent of women reported experiencing food cravings when they weren't on a diet; once they started restricting kJs, that figure went up to 94 per cent. The good news: unlike, say, your mum's constant probing about grandkids, these tormentors can be fended off. The reason? Blood sugar. If your levels stay consistent throughout the day, your eating patterns probably will too. It's when you starve yourself that cravings call.

"Your blood sugar can fall too low after just four hours of not eating," says registered dietitian Valerie Berkowitz. So you scour the fridge or the food court for simple carbs to give you a quick boost. Trouble is, the resulting blood-sugar spike triggers your pancreas to release insulin, a hormone that not only lowers blood sugar but also signals your body to run through the craving cycle over and over. In about half of us, insulin tends to overshoot - that's what sends blood sugar crashing. "This reinforces the binge because it makes you crave sugar and starch again," Berkowitz says. In other words, giving in to a craving only leaves you wanting more.

If you feel like you're addicted to doughnuts, maybe you are - New Zealand scientists have discovered that high-GI foods trigger a sugar rush that's addictive. Researchers from the Auckland Regional Public Health Service found the high blood-sugar spike caused by high-GI foods stimulates the same areas of the brain associated with addiction to nicotine and other drugs. Lead researcher Dr Simon Thornley says evidence demonstrated that people who OD on high-carb foods experience symptoms of addiction like loss of control, desire to consume more to get the same effect, and withdrawal when going cold turkey.

So, how to prevent the slow slide towards Doughnuts Anonymous? By following these steps designed to stop 99 per cent of cravings before they start - and help you muzzle the one per cent that never seems to shut up.

Ramp up your resolve

One reason most diets fail is that long-term goals can be deceptively difficult. If the plan is to watch what you eat for the next six months, chugging one caramel latte with cream seems like a minor slip. To avoid that kind of thinking, commit to eating well for a fixed amount of time that you're 100 per cent confident you can manage, even if it's just a few days. "Once you make it to your goal date, start over," says Dr Mary Vernon from the American Society of Bariatric Physicians. "This establishes the notion that you can be successful and gives you a chance to notice that eating better makes you feel better, reinforcing your desire to continue."

Find meaningful motivation

If the main purpose of your weight-loss plan is cosmetic - ie, to look amazing in skimpy boardies - you're unlikely to stick to it for the long haul. The solution: "Arm yourself with additional motivators," says Dr Jeff Volek, a registered dietitian. He suggests keeping a daily journal in which you monitor migraines, heartburn, acne and sleep quality in addition to body measurements and the number on the scale. "Discovering that your new diet improves the quality of your life and health is powerful motivation," Dr Volek says.

Go for low

Since high-GI foods have been found to be addictive like ciggies, the researchers from Auckland Regional Public Health Service say it might help to take a smoker's approach to quitting: "Just as slow-release forms of nicotine [through patches] help smokers recover from addiction, low-GI foods may reduce cravings in obese or overweight populations," wrote Dr Thornley and colleagues in the journal Medical Hypotheses. Foods to load up on: hummus, Nutella, cherries, peaches and sweet potatoes. And avoid: white bread, spuds, pretzels and white rice. For lists of low-, medium- and high-GI foods, check out the-gi-diet.org/lowgifoods.

Move on quickly

OK, you overindulged. What's the next step? "Forget about it," says James Newman, a nutritionist at Tahlequah City Hospital in Oklahoma, US, who followed his own advice to shed 136 kilograms. (That's right, 136.) "One meal doesn't define your diet, so don't assume that you've failed or fallen off the wagon," he says. Institute a simple rule: follow any "cheat" meal with at least five healthy meals and snacks. This ensures you'll be eating right more than 80 per cent of the time.

Roll out of bed and into the kitchen

Yep, you've heard this advice before. But consider that if you sleep for six to eight hours and then skip breakfast, your body is essentially running on fumes by the time you get to work. And that sends you desperately seeking sugar, which is usually pretty easy to find. The most convenient foods are typically packed with sugar (doughnuts, smoothies) or other quickly digested carbohydrates (McMuffins, scones). Which brings us to our next strategy.

Restock your shelves

How many times have you driven to the supermarket at 9pm to satisfy a craving? Probably not nearly as often as you've raided the fridge at home, mid-movie. You're more likely to give in to a craving when the object you desire is close at hand. So make sure it's not. Toss the junk food and restock your cupboard and fridge with almonds and other nuts, cheese, fruit and vegetables, and canned tuna and salmon. And do the same at work. "By eliminating snacks that don't match your eating plan and providing plenty that do, you're far less likely to find yourself at the vending machine," says Dr Christopher Mohr, a fitness and nutrition consultant.

Think like a biochemist

Cookies made with organic cane juice might sound like something your yoga teacher would eat, but they won't help her fit into her Lycra pants. Junk food by any other name is still junk. Ditto for lots of "health foods" in the mung-bean aisle. "Natural" sweeteners like honey raise blood sugar just like the white stuff. "If you're going to eat cookies, accept that you're deviating from your plan, and then revert to your [eating plan] afterwards," Berkowitz says. Kidding yourself will only get you into trouble.

Spot hunger impostors

Got a burning craving for lollies even though you ate just an hour ago? Imagine sitting down to a large, sizzling steak dinner instead. "If you're truly hungry, the steak will sound good, and you should eat," says Dr Richard Feinman, a professor of biochemistry at SUNY Downstate Medical Centre in Brooklyn, US. "If it doesn't sound good, your brain is playing tricks on you." His advice: change your environment, which can be as easy as stretching at your desk or turning your attention to a different task.