Paging Dr. Frischer: Fasting

Today’s subject is among my least favorites: not eating!

Fasting is currently a hot diet trend, but it is not new; it has been practiced for thousands of years. It is a time-honored tradition in many cultures and religions. Creative minds and spiritual leaders believe that fasting can lead to clarity, enlightenment, and energy. Fasting has a long history of being used as a tool for political protest and resistance. Medically, it is used for diagnostic testing and observation, as well as a therapy for various conditions, including obesity.

It’s very clear that the American diet isn’t working - and hasn’t for a long time. The number of obese Americans has now overtaken the number of merely overweight Americans. Is fasting an answer?

During a fast, all consumption (or consumption of certain foods or drinks) is stopped. Fasting for a day per week, as some dieters and even bodybuilders practice, does not appear to have serious physiological effects, but there are alternatives. The most dangerous fasts incorporate laxatives, or are an absolute fast, which includes no liquids at all.

During a fast, the body has no new supplies of carbohydrates, protein, minerals, and vitamins (apart from those contained in water or juice, if it is not an absolute fast). The fasting chemically begins when the body has used up all available energy from its food stores, and begins turning to the carbohydrate (fat) stores.

The body will eventually run out of carbohydrates as well, and then must look elsewhere for energy to perform the most basic tasks - including walking and breathing. The protein stores are next, which are found in the muscles and eventually the organs. The body is now technically starving.

 These are the potential benefits to fasting:

·The body will burn fat, leading to weight loss.

·A detox will occur: fat stores contain not only carbohydrates, but also chemicals absorbed from the environment. When fat is burned, these accumulated toxins are released and eliminated in the urine.

·Many people feel an increase of energy, since energy is not being used for digestion. That energy is theoretically available to other body processes such as the immune system, which can help heal the body and repair wounds; protein synthesis, which repairs damaged cells; and for the production of growth hormone, a chemical produced to trigger the building of tissue and healing of wounds.

·The BMR (basal metabolic rate) drops. This is the rate at which the body uses energy to perform basic bodily functions such as breathing, controlling temperature, etc. When this rate drops, the core body temperature also drops and the body becomes more efficient.

·Intermittent fasting can lead to increased insulin sensitivity. Insulin helps to control blood sugar.

·Extended fasts can reduce LDL (bad cholesterol levels) and improve lipid profiles.   

However, there are many ways in which fasting can cause harm:

·The body requires more than just carbohydrates to run efficiently. It also requires protein, vitamins and minerals. These are not stored in fat, so while fasting, there are none available.

·When the BMR slows and the body conserves energy, it actually becomes more difficult to lose weight. With supplies of carbohydrates scarce, the body stores more available calories as fat. Note that a widely fluctuating weight is worse for the heart than is a stable high weight.

·Blood sugar levels drop, resulting in lethargy.

· Blood pressure tends to drop, which can cause dizziness.

·Many medications will have an exaggerated affect. Taking medication that requires food can be dangerous.

·When the stomach is empty, its acids are more likely to burn the lining.

·Using laxatives while fasting can result in extreme dehydration and electrolyte imbalances.

·Absolute fasting can result in cramps, headaches, and a dry mouth and throat.

·Pregnant women and nursing mothers should never fast, as their bodies are under increased caloric and physical demands. Those suffering from kidney or liver disease, currently malnourished or anemic, have a weakened immune system, high blood pressure, medication-dependent diabetes, or a number of other medical conditions absolutely must consult their doctor before attempting any fast.

·Extended fasting can lead to electrolyte imbalances, thinning hair, cardiac arrhythmias, renal failure, and starvation, ultimately resulting in death.

If you choose to fast, how can it be conducted safely?

·The body is used to going overnight without any food. Set a small goal of fasting through one meal, such as breakfast. Pay close attention to your emotions, energy, and thoughts. If you feel good, try fasting through lunch, and if you still feel good, fast through dinner.

·Instead of eliminating all food and drink, include liquids or fruits. Experiment with different food items.

·To prepare for a fast, gradually reduce the density of your meals. Eat fresh, light, plant-based meals. Stop eating after a certain evening hour, and drink a full glass of water upon waking. This may make the transition easier.

So, should you fast? Consult with your doctor and discuss whether there is a valid and justifiable purpose. Be sure that it is safe for your body, given your own underlying health issues and medication requirements. Fasting for weight loss can work, but so can a number of other approaches, including a low carbohydrate diet and a range of well-designed diet and exercise plans. 

Dr. Alan Frischer is former chief of staff and former chief of medicine at Downey Regional Medical Center. Write to him in care of this newspaper at 8301 E. Florence Ave., Suite 100, Downey, CA 90240.