The Only Fat Burners That Actually Work (and Other Ways to Fight Flab)


Can fat burners help you lose weight? We investigate thermogenics, and their alternatives

Nick Hutchings
5 Oct 2015

If you’re looking to shed weight fast, fat burners are becoming an increasingly popular option. From the promises that most adverts make, you’d be forgiven for thinking fat burners are magic pills that melt away excess fat as you sit at your desk. In fact, they’re designed to speed up the rate you can lose weight when combined with a healthy diet and regular exercise.

Going off course on your diet is one of the biggest stumbling blocks for people who are trying to lose weight, especially thanks to the increased appetite that comes with frequent exercise. Though you’ll still need a healthy dose of willpower to combat bad food decisions, fat burners can help by suppressing your appetite and keeping up your energy levels even on a calorie-restricted diet – making it much easier to make healthier food choices.

Fat burners (or thermogenics as they’re otherwise known) aren’t for everyone, though. Their high caffeine content can play havoc with your sleep patterns, while some of the ingredients can have more serious, unwanted side effects if they’re not taken properly. Here, we take a closer look at the benefits and disadvantages of fat burners and how to use them safely, as well as offering some alternative fat-torching supplements for you to consider.

You'll also want to combine them with a sensible diet, read our lean in four weeks diet plan for a good place to start.

What are they?

Fat burners are blends of herbs and stimulants that slightly increase your body temperature, which can help you to burn more calories during exercise. Ephedrine, a synthetic version of the Chinese herb ephedra, used to be a key ingredient, but it’s now only available on prescription in the UK because of its harmful side effects and addictive qualities.

What do they do?

Some fat burners simply burn calories as heat. Others also claim to stimulate the release of adrenaline, increase your metabolic rate or act as appetite suppressants. The evidence for them working is limited, though. ‘A careful calorie intake and exercise are likely to produce better weight-loss results in the long term,’ says nutrition expert Anita Bean.

Who should take them?

‘Fat burners raise cortisol – a stress hormone – so if you suffer from anxiety it could make things worse,’ says strength coach Gregg Marsh. ‘If you think you need them, consult your doctor first.’

How much should I take?

Follow the instructions on the bottle, but be careful if you’re planning to use them over a long period of time. ‘Take them on a rotation cycle of 14 days on 14 days off for only two cycles every eight weeks,’ advises Marsh.

When should I take them?

Most fat burners contain caffeine and will make you jittery, so taking them in the morning is probably best. ‘Never take fat burners after 2pm because they affect sleep patterns,’ says Marsh. Other than that, go with the recommendation on the bottle.

Do they have any side effects?

‘Taking high doses of ephedrine can have serious effects, including palpitations, anxiety, insomnia, vomiting and dizziness,’ says Bean. ‘While herbal alternatives are generally safer, you may get side effects with high doses – some can raise blood pressure or cause heart disturbances.’

What are the alternatives?

If thermogenics aren't right for you, here are some of the best alternative fat-burning supplements on the market…


If burning fat during a workout is your priority, first you need to mobilise it. L-carnitine is an amino acid that transports fatty acids into the mitochondria – our internal power plants – to produce energy. Take a single dose of 500-3000mg before your workout to ensure that you transport the maximum amount of available fat for fuel during exercise. It’s especially useful if you’re training fasted or on a low-carb diet where fat oxidation is already maximised.

Green tea

One of the best natural fat-burners around, green tea can give your metabolism a jolt. It’s also packed full of antioxidants and has been linked to the prevention of everything from heart disease to Alzheimer’s. Drink it instead of regular tea or diet soft drinks for a huge variety of health benefits.


Anyone training intensely is likely to be under some serious stress. The stress hormone cortisol, which is responsible for fat storage, is secreted in high amounts as a result, but phosphatidylserine blocks its secretion. This allows you to recover quicker, burn more fat and build more muscle. Take it after your workout or in the evening, especially if you’re training at high intensity or particularly prone to elevated stress levels.

5 of the best natural fat burners


How they help to burn fat: Researchers at Scripps Clinic in California found that eating just half a grapefruit before each meal can help you to lose weight, up to half a KG per week, even if you keep your diet exactly how it is now (assuming that you don’t eat junk food 3 meals a day). The author of the study Ken Fujioka, says that there is a key compound in grapefruits that helps to regulate insulin, a fat-storage hormone. “Anything that helps lower insulin can help people lose weight,” he explains. “Grapefruit seems to be one of those foods.”

How to work them into your diet: Peeling and segmenting is the most obvious way to get the goodness out of a grapefruit. Try cutting it into chunks and adding to a spinach salad or simply grab a spoon and eat as is, if you can handle the bitterness.


How they help to burn fat: Eating a handful of almonds each day, alongside a healthy diet plan is quick and simple way to burn fat according to research published in the US International Journal of Obesity. Participants in the study who ate almonds on a daily basis for a period of six months found that they lost 18% of their body fat. Those who followed a diet with the exact same amount of calories and protein but swapped out almonds for an equal number of calories in complex carbohydrates (like bread) only lost 11% of their body fat.

How to work them into your diet: The perfect at-your-desk snack, grab a handful of these if you fancy a little nibble, they can be quite addictive. Alternatively, chop them up and add them to your morning porridge.


How they help to burn fat: A bit of a forgotten fruit. A study by the University of Rio de Janeiro revealed that people who ate three pears per day consumed less calories each day and also lost more weight than those who didn’t. They’re very rich in fibre (with one pear packing in 15% of your daily recommended amount), pears will help you to feel fuller for longer thus keeping you from overeating.

How to work them into your diet: Be sure to keep the skin on them as it holds most of the beneficial fibres. Pears make a great addition to a leafy salad, especially when combined with a bit of blue cheese.

Navy beans

How they help to burn fat: Loaded with resistant starch, the relatively unheard of navy beans are a very powerful fat burner (half a serving contains nearly 10 grams of resistant starch). Researchers at the University of Colorado found that if you eat navy beans or similar foods high in resistant starch levels just once per day you could burn 25% more fat than you would without them.

How to work them into your diet: Try sautéing some shallots and garlic in olive oil, throw in a couple of cans of drained navy beans, mixed it all up in a blender to puree and serve.


How they help to burn fat: Yes, chocolate. Hear us out. Dark chocolate, and other foods that are high in antioxidants have been proven to help prevent the build up of fat cells in the body, a precursor to obesity and heart disease, this is according to new research from the Taiwanese Journal of Food Chemistry and Agriculture.

How to work them into your diet: It’s chocolate. Do we need to tell you? Just try not to eat too much of it, kind of defeats the object. 

Extra info

Here are the experts who gave us an insight into fat burners:
Anita Bean is the author of The Complete Guide To Sports Nutrition (£15.99, A&C Black Publishers). For more visit
Dr. Lonnie Lowery is an exercise physiologist, nutrition expert and former competitive bodybuilder. He is also a licensed dietician specialising in sports nutrition.
Nikhil Rao is a trainee doctor, avid weightlifter and regular contributor to the US bodybuilding site He has been using creatine for six years.
Gregg Marsh is a strength and conditioning coach, personal trainer and nutrition consultant. He has more than eight years of experience in nutrition. For more visit

Finally, here are three super effective types of fat-burning training protocols, each with a sample workout, to complement all the natural fat-burning foods we've mentioned above.


This stands for as many reps or rounds as possible, depending on the type of workout you're doing. You do these workouts for time so the emphasis is going as hard as you can for the proscribed period, with as little rest as possible. This creates a massive energy demand, which – you guessed it – torches loads of calories. Here's an AMRAP from top PT David Arnot for you to start with: As many rounds as possible of 10 kettle bell swings and six burpees in five minutes.


Short, vicious, and bloody fantastic on the fat loss front. These four-minute high intensity interval workouts comprise eight rounds of 20 seconds of work and 10 second of rest. And you can do them with almost any move that has an explosive element to them. 'Not only does it increase fat burning, it's also a great tool for building mental strength, because getting through tabatas is a real challenge,’ says MF cover model and trainer Sean Lerwill. Try this tabata workout to get you started with the protocol: Eight rounds of 20 seconds of maximum intensity rowing, followed by 10 seconds of rest.


Fat Loss 4 is a workout protocol made up of four moves performed back-to-back in a circuit of just five minute. You'll do 30 seconds of an upper body compound move, followed by a 15-second rest; 30 seconds of a lower body compound move, followed by a 15-second rest; 30 seconds of a core move, followed by a 15-second rest and one minute 45 seconds of a high intensity cardio exercise followed by a one-minute rest. 'This works your entire body and massively raises your heart rate over a short period of time, which fires up you fat-burning metabolism during a session and keeps it working for hours afterwards too,' says PT Will Girling. 'Try this leaning FL4 workout: Four rounds of pull-ups, squats, Russian twists, and a row.'

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