Too Long, Didn't Read Version
- Weight loss is not the same thing as fat loss. When you lose weight, it can be a mixture of both lean mass and body fat.
- To force your body to burn only FAT, you need to resistance train and eat an adequate amount of protein.
- Exercise burns much less calories than most people estimate and is an inefficient way of creating a calorie deficit. Dieting should be the main method of creating a deficit.
- Because cardio does not protect you from muscle loss, the best form of exercise to assist in FAT loss is resistance training. Exercise designed to "burn calories" should come secondary to resistance training.
- The best method to lose body fat: Eat less calories and use resistance training as your primary exercise. Cardio can be done to assist the rate of fat loss.
Losing body fat tops the list of fitness goals. With this popularity comes a lot of false advertisement, exaggerated claims and just plain bad information. You'll often see a workout that is focused solely on burning calories, such as cardio or circuit training being touted as the "best fat burning routine!". I’m here to tell you that this type of routine, while useful, is NOT the optimal type of routine that you should be performing for fat loss.
Weight Loss vs Fat Loss
In order to understand how you should train for fat loss, we must first understand one important concept, which is the difference between fat loss and weight loss. Just because you're losing weight does not mean that you are losing only fat, or even mostly fat. If you lose weight without exercise, you risk muscle loss .
In order to reduce your body weight, you must eat less calories than your body burns in a day , but when you do this without proper exercise and protein intake, your body can get it's energy source from not only body fat stores, but also other areas of the body such as lean body mass (muscle, bone, etc). When this is allowed to happen, body fat becomes a smaller percentage of the weight that you lose and your body composition can suffer in the process.
Preventing Muscle Loss
So how do you prevent the body from burning off lean body mass and have it only take from body fat stores to maximize fat loss? Simple, you perform resistance training and give your body a reason to keep on to it's muscle mass or build more and then eat adequate amounts of protein to support this  .
By performing a resistance training routine, you send a signal to your body that you need your muscle, making your body less likely to get it's energy sources from lean body mass and more likely to get it from fat stores when you lose weight. This creates a situation where you are burning off nearly 100% body fat while maintaining or building muscle, which will have a much more positive impact on your body composition and appearance. This is the result that everyone really wants when they say they want to lose weight.
This is the reason why performing a cardio only routine or other types of aerobic exercise is NOT the optimal way to train while trying to lose body fat. By focusing too much on workouts that "burn a ton of calories" as opposed to actually working and strengthening your muscles, all you're doing is causing a larger calorie deficit while doing nothing to actually force your body to burn a higher percentage of body fat, resulting in more muscle loss. If two people lose the same amount of weight, but one performs resistance training while the other doesn't, the person who resistance trains will lose more body fat overall and have a more positive change to their appearance.
Diet vs Exercise For Reducing Calories
In general, people put too much attention on trying to burn calories through exercise and activity and too little attention to their actual diets. In truth, it is much more efficient to reduce calorie intake first, before trying to increase how much you're burning. Exercise is relatively inefficient at causing a negative energy balance alone, because it actually burns less calories than most people expect it to and it's notoriously hard to accurately calculate the calories burned. Think about it this way, is it easier to eat one less slice of pizza or going jogging for a full 30 minutes? Either one will cause your net energy balance to be reduced by roughly 300. It makes much more practical sense to use your diet to create the bulk of your energy deficit and then use cardio as a secondary method to further increase calories burned.
Your diet should be your main tool to lose weight, while exercise should be used for two purposes. The first and primary focus being to prevent muscle loss and to facilitate FAT loss through resistance training. As a secondary form of exercise you should do cardio only to assist in creating a slightly larger deficit by burning calories. Cardio, however, is actually not even required at all, but can be helpful in speeding up the process.
Take Home Point
It essentially boils down to this: Your diet should be your primary method of creating a caloric deficit, while resistance training should be your primary method of exercise to facilitate fat loss as opposed to just simply weight loss. Cardio is optional to help speed up the rate of fat loss and is not required at all for losing body fat. Routines that claim to be "fat burning" or "calorie burning" routines are not optimal because they're too aerobic in nature to facilitate muscle growth and maintenance, thus they do nothing to actually help optimize body fat reduction.