Burning more calories than consuming is the most basic principle of weight loss. If intense workout sounds too hard for you, then the best way to achieve that weight loss target is to simply consume a whole lot fewer calories. However, while taking this decision, you need to remember that cutting too many calories can actually have the opposite effect, completely stalling your weight loss efforts.
Thus, understanding the difference between consuming fewer calories and starving self is of utmost importance. To begin with it, the first things you need to know is resting metabolic rate (RMR), or the number of calories your body burns at rest.
If you cut down calories without considering your RMR, the first thing that’ll happen is that your RMR will also drop. Energy is required not only to fuel your body but brain too. Here you need to know that your brain is fueled by glucose—the sugar molecule that is regulated by eating—and your body will do anything it can to keep your brain up and running.
If you continue at this too-low intake of calories for more than a day, your body will start to break down muscle tissue to get the amino acids stored here, which it can then convert to glucose. Dropped RMR means that your body will go into an energy saving mode, making you feel lethargic. Moreover, your body breaks down fat by oxidising it in the mitochondria, in order to do this, you need energy from carbohydrates to shuttle the fatty acids into the mitochondria. Thus, no carbs, no fat burn.
Apart from it, there are peripheral consequences of under-fueling yourself. If your blood glucose drops too low, then you also face a cascade of problems like increased appetite and cravings; poor sleep, which will then elevate cortisol, leading to more cravings, more muscle loss; and fatigue.
Thus, the trick to weight loss is to eat just enough calories to keep your blood glucose level within normal ranges. The general rule of thumb is to cut about 25 percent of your baseline RMR—so 500 calories per day from a 2000-calorie diet. This is generally enough to get the weight loss going. According to experts, cutting 500 calories a day can help you lose a pound a week.