If weight loss is your goal ‘Energy Balance’ is what should be your focus. Understanding energy balance is the main determinant of weight management. An energy surplus equates to an increase in body mass, and an energy deficit equates to a decrease in body mass.
In order to improve body composition, the main goal must be to decrease body fat while keeping caloric intake as high as possible. This will provide you with enough calories to minimise any loss of lean body mass and create a greater caloric bank to draw from to combat plateaus. Crash diets don’t work according to research!
The most common mistake people make when attempting to shed fat is simultaneously reducing caloric intake and increasing exercise energy expenditure. The problem with this strategy is it creates a magnified energy deficit caloric reduction plus increased energy expenditure and it reduces your “caloric bank.” If you’re in a magnified caloric deficit, you will lose body mass too fast to maintain lean body mass, which in turn will negatively affect your basal metabolic rate (i.e. the amount of energy your body uses for basic life function.
Regular exercise allows you to eat more food without gaining weight and can also have a small impact on weight loss. If you just diet in order to lose weight and do no exercise you could end up being skinny fat as you are not doing anything to ensure you keep/build your muscle mass or firming up what you have. Use it or you’ll lose it.
Also the ability to train effectively during each training session is really what builds lean muscle, cranks up your metabolic rate, and allows you to burn more calories during the other 23 hours of the day that you’re not training. To train effectively and truly maximise every training session, you must be properly fuelled. When attempting to reduce body fat, many people utilise calorically restrictive diets that interfere with their ability to maintain adequate training frequency, volume, and intensity. Intense training without the proper fuel blunts progress.