Is Your Diet Supplement Doing Anything? | Men's Health Magazine Australia

Is Your Diet Supplement Doing Anything?

Swallow the advertising spiels whole and you’ll conclude that fat-burners are a “rapid-fire” solution to “incinerate” your body fat and generally build the physique you want without too much effort. Clearly the marketing bumph works, with the fat-burner market exploding on these shores. But with an ever-lengthening list of ingredients and synthetic-sounding chemicals, can you really pinpoint the effects of the pills you take? MH pored over the science to find out whether you should keep on popping or watch the habit.


A highly popular chemical in fat-burners, glucomannan has an instant effect on your appetite. It’s a thickening agent, so absorbs liquid and expands in the stomach to super-size your meals from the inside out. The result: you feel full for longer. The effect sounds extreme, but actually it’s no different to thickening soups. Still, while it’s been proven to combat obesity, there are noticeable side effects. We’d advise staying close to the facilities . . .


Green tea extract is one of the more natural options when it comes to giving your metabolism a boost. Containing plant-derived polyphenols, it increases your liver’s ability to process dietary fat. And in the short-term this works, helping to kickstart your weight loss. But be cautious – it also bumps up the caffeine count, too much of which can irritate your stomach. Don’t wash it down with an espresso.


“Fat-binding” pills stick to fat molecules, allowing them to pass straight through your system. But in doing so they also scoop up essential nutrients. “This can result in the malabsorption of fat-soluble vitamins A, D, E and K,” says pharmacologist Dr Igho Onakpoya. Digestive issues – exacerbated by the aforementioned caffeine hit – can also lead to imbalances in sodium and potassium. Not the kind of losses you want.


Fat-burners’ diverse mix of ingredients can make you urinate more frequently, resulting in calcium loss. Some try to compensate with extra calcium, but this can overcrowd your intestines, interfering with zinc and iron absorption and affecting carb breakdown. Which, in turn, can make your workouts feel tougher. In short, a sensible dose is fine for a short-term boost. But if you train dirty, you’re better off staying clean.

The Above Average Joe

We weigh up three popular metabolism-boosters to see how a one-gram dose stacks up against your daily fat-burning stalwart, a cup of coffee.

Green tea extract

= 288% metabolism increase

= 10 cups of coffee


Bitter orange extract 

= 50% metabolism increase

= 1.7 cups of coffee

Cayenne pepper

= 2% metabolism increase

= 0.1 cups of coffee

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