Losing body fat is easily one of the top fitness goals among people who start a workout routine. It’s THE number one reason why anyone tries to change their diet. In fact the term “diet” refers to eating in a way that facilitates fat loss.

By this point it’s become general knowledge that your body loses weight if you burn more calories than you consume or if you consume less calories than you burn (known as energy balance). Although I am a big believer that it’s not only about energy balance and that things like hormone fluctuations and your gut microbiome can influence fat loss, it’s pretty crystal clear (based on mounds of scientific evidence) that energy balance plays the BIGGEST role in determining whether or not you lose weight or gain weight. In other words if you are consuming more calories than you burn nothing will make your body lose weight. This is a simply law of physics...you can’t lose weight if your body has excess energy and you can’t gain weight if your body isn’t provided with enough energy.
Ok, now that we have made that fact clear, I want to address the BEST way to work with calories to get your body to BURN THE MOST BODY FAT. I’m not going to talk about macro nutrients (proteins, fats and carbs) in this article although they are also extremely important factors to consider, second only to total calories. I’m going to assume you have a good idea of how many grams of each of the macro nutrients you need to consume while in a calorie or energy deficit for your own body.

When people understand that they need to eat less than they burn or vice versa to lose weight they tend to apply this knowledge in a very straightforward daily consistent way. Here is an example...

Let’s say you figure that your body burns 2500 calories every day. Since you want to lose weight you decide to consume 2000 calories every day thus putting your body at a calorie deficit of 500 calories. In other words you are burning 500 more calories a day than you are eating. This results in some fat loss and it’s pretty straightforward. It’s also not the best way to approach your diet.

When you do ANYTHING super consistently, your body adapts quickly. If you are consistently consuming 500 calories less than you are burning your body will aim to become more efficient with calories to make up the difference. Remember, your body does NOT want to burn tissue and this includes fat. It would rather store it and keep it in case of a famine. Since you are consuming less calories than you are burning, your body SLOWS down its metabolism to adapt. This is known as metabolic adaptation and it’s a real thing. Your metabolism has an uncanny ability to slow down to adapt to a low calorie diet and this is the main reason why diets work for a short while but then stop working entirely. Your body simply adapted.

An effective dietary strategy to offset this is to look at your total weekly calories and to alternate between days with a bigger caloric deficit, a smaller deficit, some maintenance days and even some days where you eat a little more than you burn. In my experience this LESSENS the metabolic slow down that occurs with regular dieting. Here is an example:
Let’s say you burn 2500 calories a day. You want to average 500 calories UNDER what you burn. That’s a total of 17,500 total calories consumed for the week. You want a 3,500 calorie deficit for the week (500 a day). Instead of simply eating 2000 calories every day, mix up your intake. Have some days be 1500 calories and have others be 2500 calories or 2000 calories. Ultimately the goal is to hit the same targets for the week.

Here is a comparison of both options:

Option one (less effective)
Monday through Sunday
Body burns 2500 calories a day.
Eat 2000 calories daily for a total of 14000 calories consumed for the week for a deficit of 3500 total calories.

Option two (more effective)
Body burns 2500 calories a day
Monday 
1500 calories
Tuesday
2000 calories
Wednesday
2500 calories
Thursday
1500 calories
Friday
1500 calories
Saturday
3000 calories
Sunday
2000 calories
Body burned 17500 calories for the week
You ate 14000 total calories for the week
Total deficit 3500 calories

The second option will result in a faster metabolism and gives you some days where you get to consume more food! It also more clearly self mimics how real life works. Overall it’s a more effective strategy or both your body and your mental state.