Everything You Need to Know About Burning Fat (Plus the Stuff That's Worth Forgetting)
Is fat loss a complex feat of biochemistry, or an elementary case of eating less and moving more? Neither view is fully satisfying. You don’t need to enter ketosis or subsist on alkaline water to drop a couple of kilos – but there are some clever cheats that can help. This is your primer on the theory and practice of fat burning. Call it your cutter’s choice

01 Losing game When your body requires more energy than you’re putting in, it breaks down the molecules in fat cells to burn them for fuel. Most of what you “lose” is exhaled as carbon dioxide, while the rest is lost as water.

02 The slow burn Quick weight loss causes your metabolism to drop, as your body fights to conserve energy. But that doesn’t mean you’re doomed to a life of lentils. Try intermittent fasting: a study in Plos One noted an increase in calorie burn among men who ate larger meals, less frequently.

03 Seek small victories Even men of a regular BMI with excess fat around their middles are at a higher risk of heart disease. Losing 5-10% of your weight – say, from 89kg (14st) to 83kg (13st) – lifts your odds. Losing just 3kg can have a similar effect on your blood pressure as a hypertensive tablet would.

04 Maintain your gains If you’re not eating enough, it will be hard for your body to synthesise new muscle tissue. A study in Obesity found that when people followed an extremely low-calorie diet, 18% of their weight loss was actually from muscle. Keep your deficit at 500kcal or less.

05 Swerve the crash Losing fat improves your body’s sensitivity to insulin, rebalancing appetite and energy. But when you’re starting a new fitness plan, post-training blood-sugar crashes are common. Factor in a carb refuel to fight back the urge to binge.

What Happens When I Lose Weight?

Think about it in terms of gains, not losses. Dropping a little excess body fat can give your health markers a lift on multiple levels


Your muscles contribute to a hefty 20% of your metabolic rate, according to the International Journal of Obesity, while your fat mass uses up a mere 3% of your energy. That means adding muscle through strength-building exercises is crucial to staying lean.

Don’t Miss a Beat

Keeping your heart rate in the fabled “fat-burning zone” is said to accelerate weight loss. But do proponents have their fingers on the pulse? Leading exercise physiologist Tom Cowan* decodes the science

“Whether you’re pacing around the office or running on a treadmill, contracting your muscles requires energy. This energy is derived from a mixture of stored fat and stored carbohydrate, which is found in the muscles and liver as glycogen. At lower intensities, fat is your fuel source. However, as the intensity of your work ramps up, a greater proportion of this energy comes from carbs. The fat-burning “zone” is a point around 60-65% of your max at which your body is oxidising the biggest amount of fat possible.

“Here’s the rub: that doesn’t mean it’s the best way to get leaner. Weight loss is predominantly determined by calorie balance, regardless of how those calories are stored. Burning glycogen isn’t inherently inferior. For the best results, you need to vary your training intensity, working in multiple heart-rate zones, so you can easily tap into either energy source.”


“Most foods contain a mixture of both types,” says nutrition consultant Steve Grant. “It’s not one way or the other.” What’s more, the sat fat in grass-fed rib-eye contains roughly the same calories as the supposedly healthier salmon. Plus, feta weighs in lighter than nuts.

Choose It to Lose It

Q1 How do you feel about carbs?

A Not too fussed Go to Q3

B I like my bread Go to Q2

Q2 But could you give it a break?

A I’d cave within day Go to Q6

B Yes, if I had to Go to Q4

Q3 Ever tried going vegan?

A Are you serious? Go to PALEO

B I’m partial to a chickpea curry Go to Q5

Q4 Do you eat out a lot?

A Yeah, a fair bit Go to Q5

B Only if Pret counts Go to Q6

Q5 Are you hungry before 10am?

A I’m always hungry Go to PALEO

B Very rarely Go to 16:8

Q6 Are you a feaster or a grazer?

A I’m a big meal man Go to 16:8

B Habitual snacker Go to CICO

PALEO No missed meals or stingy portions here. This plan, modelled on the foods we (supposedly) ate in the Palaeolithic period, eschews processed foods and grains for meat, veg, fruit and nuts. Purists swerve legumes, too, but the extra carbs can benefit your training. A Brazilian study found that going paleo led to 3.5kg of weight loss, largely by boosting satiety.

THE 16:8 Best suited to the sort of man who often “forgets” to eat when he’s busy – or enjoys a big lunch/dinner. Simply limit your calorie consumption to an eight-hour window (eg 12pm to 8pm), ensuring your gym sessions are in sync, so you’re never skipping your refuel. A 2017 study found it led to greater fat-loss in men than simply reducing portions.

CICO This stands for “calories in, calories out”. No food is off limits, so long as you burn it off over the day – but you’ll need a fitness tracker to keep tabs on your output. You need to ensure you’re eating enough protein (100g) and fibre (30g) to support post-exercise recovery and satiety. See page 100 for #inspo.

The Drugs That DoWork

Carb-blockers and stimulants are more likely to give you stomach cramps than a six-pack. The best fat-loss drugs don’t sell themselves as fat-loss drugs. Here’s our daily supps plan

6am Multivitamin Keep it simple and cover all bases. Falling short of your micronutrient RDIs – particularly mood-supporting vitamin D and energy-boosting B – contributes to fat gain.

8am Caffeine Whether taken as a smooth flat white or a punchy cold brew, caffeine improves your mood, energy and exercise motivation. Useful for your power walk into work.

11am Phenylalanine Taken 30 minutes before a workout, this amino acid can improve your fat usage. It’s also linked to a reduction in cortisol, a stress hormone that triggers weight gain.

2pm Inulin Powder Add this potent prebiotic to your afternoon shake. It’ll keep your gut bacteria healthy, which in turn will ensure that your metabolism is firing on all cylinders.

9pm Magnesium Spray Finally, spritz this on the back of your knee (where your skin is thin) before bed. High-quality sleep is crucial for supporting fat loss. This will help you get it.

Your Calorie-Crushing Crucible

With a kettlebell and a few metres of space, this brutal circuit – from MH’s World’s Fittest App – engages the huge muscle groups of your lower body to torch as much fat as possible. Make it through each set without dropping the bell. Shoot for four rounds

01 Swing

20 reps

Begin by hiking the weight back between your legs, bending only slightly at the knees. Thrust your hips forward to propel the weight up to eye level. Control the return and flow straight into the next rep. Perform 20, then move on with no rest.

02 Goblet Squat

15 reps

Stand with your feet shoulder-width apart and hold the bell by the sides of the handle, under your chin. Drop into a squat: keep your back muscles switched on to fight the urge to lean forward. Drive through your heels to stand back.

03 Lunge

10 reps

Grab a second kettlebell and stand tall, holding them by your sides. Lunge forward with your back straight until your rear knee touches the ground, then push back up to starting position. Repeat on the other side and alternate.

04 Kneeling Press 10 reps

Begin in a half-kneel, your left leg forward and a kettlebell in your right hand, in the front rack. Tense your core and press the kettlebell above. Lower under control. Do five reps, then swap sides. Rest for 60 seconds, then start the circuit again.


Combining these two training methods is the surest route to sustainable fat loss. Use MH fitness editor Andrew Tracey’s guide to learn how they work – and when to deploy them – to maximise your fat loss

HIIT High-intensity interval training involves quick bursts of all-out effort, with recovery periods in between.

Use it HIIT sessions should be kept short, so it’s ideal if you’re time-poor, and they’ll hike your metabolism for an impressive after-burn. But HIIT also stresses your body, so keep it down to three non-consecutive sessions per week.

LISS Low-intensity steady state – which means keeping your heart rate at a consistent, sustainable pace.

Use it On the days between HIIT sessions, or when you have more time (30-50 minutes). It takes longer to achieve the high-calorie burn you need for fat loss but recovery is quicker, so you can train again sooner.

Unsure where to start?

Pick four exercises that, when combined, will work your entire body. Then, to ensure you never get bored, perform them using one of the two common exercise protocols below. Each can be adapted for either a HIIT or LISS training style.


Oh, 2010 called, and it wants its meal plan back. Some people can thrive on minimal carbs, but there’s no need. Aim for 1g of carbs per kilo of bodyweight in the hour after training: the optimal formula for storing those grams as muscle, not fat.

A Matter of Timing

We asked fitness editor Tracey for his No1 lesson in fat-loss nutrition. His response? It’s not just what you eat, it’s when…

“Let’s get one thing out of the way: calorie reduction remains the basis of any weight-loss diet. That’s the primary determinant of whether it’ll work. Having said that, meal timings can have a huge impact on how you’re able to use those calories. I’d always advise eating your day’s biggest meals around your training sessions – perhaps a carb-based meal an hour or so before your workout, with a hefty dose of carbs and protein afterwards.

“Ensuring you’re properly fuelled can have a huge impact on your ability to perform in your workouts, helping you push harder, last longer and therefore burn more calories, without overly depleting your glycogen (energy) stores. Whatever your eating plan, when you’re trying to reduce your intake, concentrating your calories before and after training can be a better strategy for performance and recovery than spreading them out.”


True, you can’t go at it 100% all the time. But gently training the same muscles you targeted yesterday – cycling after squats, say – can counteract pain and boost circulation, improving nutrient delivery to your quads and helping you maintain weight loss.