The word 'diet' strikes fear into the heart of everyone.

Think diet and you probably think of giving up all your favourite foods and living off chicken and broccoli for the rest of your days. One of the big problems with restrictive dieting is by depriving ourselves of things, we want them more. This creates a vicious cycle of restriction and then bingeing which is not healthy and not sustainable. But what if we told you there was a diet that would allow you to eat pizza, fries and ice cream without ruining your gains? The IIFYM diet is just that. You may well have heard it spoken about in the gym, but it basically means 'If It Fits Your Macros' you can eat it.

What is it?

IIFYM is a diet where you can eat anything your heart desires, as long as it 'fits your macros' - or your total daily calorie budget.

How does it work?

There are so many different diets out there - some you just eat juice, others you have to live off vegetables. But at the heart of them all is calories. You eat too many calories, you gain weight. You eat fewer calories you lose weight. It's science. IIFYM is based around this simple premise. It sees a calorie as a calorie - whether it comes from a doughnut or an apple. So if you're sticking to eating your exact macros - or calorie allowance - then you will hit your diet goals.

What's a macro?

Macros - or macrontrients - are the food types our bodies need in large quantities to provide energy, metabolic function, growth and many other body functions. Protein, carbohydrate and fat are your main macros (although fibre is very important to our diet where weight loss is concerned). So depending on your goals, you're going to need different amounts of these three main macros in your diet - as long as together they add up exactly to your total calorie budget. People wanting to build muscle will need higher protein while people concerned with athletic performance will need high carbohydrates. But as long as your protein, carbs and fats add up to your total, you're cool.

How do I calculate my macros?

You can calculate your own personal macro total using a series of simple formulas which take in your sex, age, height, weight and a number of other factors. This will give you a  'Total Daily Energy Expenditure' (TDEE) - at its most simple if you eat more than this you will gain weight, if you eat less you will lose weight. As we mentioned before this TDEE calorie total can then be split into your macronutrient ratios. So you might get 50% carbs, 25% protein and 25% fat making up your calorie total. It all depends on how you prefer eating and what your goals are. There's a simple calculator here that will do all the hard work for you.

Do I have to track my food?

Yes. Otherwise you won't know how many calories you're eating over the day. You'll probably end up eating too many and miss your target. Using a food tracker like the My Fitness Pal app is useful because you can key in the foods you're eating and it adds it all up for you. Pretty soon you'll know how many grams of protein a 200g chickn fillet has - or how much fat is in a 50g handful of cashew nuts. It gets easier.

Will I get lean?

If you want to get lean, then yes you will get lean. If you want to bulk up, then you will bulk up. It all comes down to how many calories under or over your TDEE you're eating. Smash 1,000 calories on top of your TDEE every day and we guarantee you'll put size on. But if you're burning through more calories than you're taking in then you will lose fat. The IIFYM website reckons 20% less calories is the optimal amount of serious fat loss.

Aren't carbs and fat evil though?

Nothing is evil on the IIFYM diet. A calorie is a calorie, remember. So the theory is that 500 calories from sweet potatoes is the same as 500 calories from pizza, as long as you're sticking to your macro limit. The bottom line on IIFYM is that if you're exceeding your macro target, you will naturally put fat on. So adherence is key and knowing exactly what you're eating will help you reach your goals.

Is it healthy?

If you're purely looking at body composition, then IIFYM will get you exactly the same results as 'eating clean'. But obviously for your overall health eating fresh, whole foods are going to be better for you that eating processed junk. Whole foods are rich in nutrients, they will keep your energy levels and blood sugar more constant and long-term they help protect against things like cancer, heart disease and diabetes. But factoring a few cheats into an otherwise health diet will keep you sane, keep your cravings at bay and make it more sustainable to stick to.

Can I eat pizza?

Yes you can eat pizza, if it fits your macros.

Can I eat ice cream?

Mate, c'mon. [caption id="attachment_65516" align="alignnone" width="597"] A bowl of chocolate and vanilla ice cream[/caption]