One sure way to lose weight, it might seem, is simply to stop eating for a while. Simple as it sounds, that idea is fraught with potential problems.
The basic weight loss equation certainly remains valid in this case: using more calories than are consumed results in weight loss. If you don’t take in calories by eating, it’s fairly easy to satisfy that equation. Your body burns 70 calories per hour even just sitting idle on the couch.
But while you may be idle, your body’s systems are not
First of all, the body – deprived of food – will slow down the metabolism and burn calories more slowly. Weight loss can be sudden at first, but the rate slows very soon thereafter.
At first, it goes after glycogen stored in the liver and converts it to glucose to burn for energy. That energy is used to power all the body’s activities.
When that is used up (to a degree), the body then begins going after the energy stored in the bonds of certain molecules in fat cells. The process is called ketosis and accounts for why your breath sometimes smells like fingernail polish (made with ketones) after hard exercise.
So far, that all sounds good. You burn calories, reduce body fat and lose weight. Exactly what you wanted. But, unfortunately, this isn’t all the body is doing under these circumstances.
Because of the relatively rapid weight loss/calorie burning from this method of ‘dieting’ the body will experience a ‘rebound’ effect. In other words, it will cause you to crave food like crazy. The food you do eat will cause you to put on more pounds than you lost. The body is compensating for a radical deficit.
At the same time, there are serious health risks to simply starving or a long term fast. Going without food for a few hours or even a day isn’t dangerous, though it can be uncomfortable since you’ll get very hungry. But this method causes a number of carefully balanced nutrients to get out of whack.
It upsets the delicate balance of insulin, sugar and a variety of other essential compounds. Apart from regulating energy levels, they influence hormones that regulate the brain and nervous system.
Concentrations of potassium and sodium get out of balance unless you compensate with sports-style drinks, which can be more difficult to adjust in the absence of food. Those minerals are key to regulating the heartbeat, not to mention being found in every cell of the body and the fluid in between where they participate in an enormous variety of vital tasks.
Fatigue, dizziness and difficulty concentrating are only three of the milder symptoms that will result. Dehydration is likely, since much of the fluid we gain is from food, not just liquid. That can easily lead to heat stroke if the weather is at all warm and you are even a little active.
The kidneys will have a more difficult time filtering properly. They clean waste material from the blood, play a role in regulating blood pressure and stimulate the bone marrow to make red blood cells.
The odds of heart attack are increased, brain function suffers,… the list is endless. Even if the fast is ended long before death (at about 4 weeks), serious physical effects would occur.
Instead of fasting, eat a balanced, healthy diet of limited calories – combined with an age and circumstance-appropriate exercise program. That is the surest way to lose pounds safely. Your short term and long term health will be in harmony.