
So everyone thinks you have to eat super clean with no junk food allowed at all to lose weight, burn fat and get cut. Well it's not true...
Everyone has a BMR (basal metabolic rate) and this is the energy you use to live, or in other words the energy you burn whilst doing no activity at all, like when you sleep.
To work out your approximate BRM you do: weight(lbs) x 10 + (weight x 2). E.g. 150lbs x 10 + (150lbs x 2) = 1800 calories BRM. Add the energy you burn with activity. E.g. vigorous gym workout = 800cal. So 800cal + 1800cal = 2600cal burnt a day. If you eat more than 2600 calories a day you GAIN weight and if you eat clean food you gain muscle but not much fat. What about losing weight? To LOSE weight you must eat less than 2600 calories a day. But theoretically you don't have to eat clean.
What is IIFIYM? Macro means large or major. Macro nutrients are your major nutrients, which are carbs, protein, fats, fibre, sugar and CALORIES. You burn 2600 a day so you must eat less than 2600 to lose weight.
E.g. we will set our calorie limit at 2000 calories a day. This means each day you lose 600 calories, which is about 1-1.2lbs of weight lost a week. As long as you DON'T go over your 2000cal limit then you WILL lose weight. Theoretically you can eat 2000 calories of KFC and Coca Cola and still lose weight because you still burn 2600 therefore lose 600 calories a day, thus it does still fit in your macros. But why is this bad?
If you were to reach your calorie limit by eating rubbish then you will look and feel rubbish. Why? It's because you still need your MICROS. Micros are minor nutrients like vitamins and minerals. These are essential for your body to function properly and produce all the little things you don't think about such as healthy hair, nails, skin etc. So if you eat rubbish and loss weight you will be actually be unhealthy. It is, in effect unhealthy weight loss. Therefore you must eat healthy 75% of the day but you can have 1 cheat meal every day, yes every day and lose weight if it fits in your macros because you are still getting your micros from the healthy whole foods. Make sense?
If you have a limit of 2000 calories a day and at the end of the day you have eaten 1500 CLEAN calories then you can have 500 calories from any food you like. You can have a 500cal bag of chips and you will reach, but not exceed your limit of 2000 calories. If you keep doing this you will lose weight but it will be healthy weight loss because you're still getting your micros from the 1500 clean calories you've eaten previously in the day so the little cheat meal doesn't hurt as long as you don't go over your calorie limit.
What if I'm a bodybuilder/someone who wants to lose fat weight and not muscle? The key is the macro protein. You must have 1g of protein per pound of bodyweight at least. 150lbs needs at least 150g of protein to gain muscle when bulking, or maintain muscle when cutting. So when you lose weight you must set a calorie limit BUT also a protein target.
E.g. Our calorie limit was 2000, our protein target was 150g. We have eaten 1500 calories and we've consumed 125g protein. We can only have 500 calories but we need another 25g of protein.
Can I have a cheeseburger? If your cheeseburger is no more than 500 calories and contains at least 25g of protein then it fits in your macros doesn't it, so yes you can.
A little extra note: if you want to go a step further and make sure you weight loss is extra healthy and successful then you can plan ALL your macros. That means you set a calorie limit and you set a protein, carb and fat target. Your calorie limit is 2000, your protein is 150g, your carbs are 200g and your fat is 20g. This means when you eat you must NOT go over 2000 calories but you must reach your targets of 150g protein, 200g of carbs and 20g fat.
In conclusion, to gain healthy muscle weight you must eat clean and you must eat plenty of protein or you will gain fat instead of muscle. However to lose weight you only have to eat clean 75% of the time as long as you do not exceed your calorie limit. To lose weight and keep muscle you must reach your protein target. For best results if you want to lose weight, burn maximum fat, have enough energy for working out and maintain muscle you must reach your protein, carb and fat targets, not just protein. When you are eating that burger and you ask can I eat this? If It Fit In Your Macros (IIFIYM) then YES!

(Remember to work out your own BMR and the calories you burn from your exercise but use the formulas at the top of the page.Yes this is calorie counting but it's easy on livestrong.com or with the app MyNetDiary)