Intermittent Fasting and its Effects on Mental and Physical Health

For most of us, it would seem counter-intuitive to willingly deprive ourselves of one of life’s basic needs: nourishment. Equally, news that fasting protocols are becoming increasingly popular these days would sound equally shocking. The intention, which is far from undermining good health, is to actually enhance it. Evidence from various sources from across the country indicates that intermittent fasting can be used as a powerful tool, producing long-term health benefits in the body and mind. Intermittent fasting affects your brain when you change your diet by drastically reducing food intake. If you choose to begin a program like this, it is important to follow one of the carefully constructed programs in order to protect your body from starving, which starts the process of burning muscle instead of fat, as well as making sure you still supply the body with safe but small amounts of nutrition, ensuring optimal brain activity.

As there is so much interest in this field, a few distinct patterns and several methods of fasting have emerged. The most popular and manageable is intermittent fasting, which involves cutting calories by 20% and limiting the hours per day when food is consumed. These time windows can vary from six to twelve hours per day. Alternatively, some people follow what they call the “5:2” diet, where they will eat normally for five days a week and eat calorie-reduced diets for two days. In a study conducted with overweight participants, those who adopted the 5:2 diet lost weight more quickly than those who were restricted to fewer than their normal calories every day. Also, the people in the intermittent fasting group cleared fat from their systems and showed a 9% drop in systolic blood pressure. The “regular diet” group showed a slight increase in blood pressure.

Traditionally, it’s common to associate any kind of dietary changes with the desire to lose weight, and people who use intermittent fasting can lose a lot of weight that stays off. Additional health benefits have been quite dramatic, even a reduced risk of certain types of cancer, including breast cancer.

Valter Longo, PhD, of the University of Southern California in Los Angeles, CA, has done extensive research on the effects of a fasting-mimicking diet (FMD), using a calorie-restricted diet for five days every 1-6 months. The time ratio depends on the recommendations of a physician for that particular person based on their health conditions and size. Participants eat a mostly plant-based “longevity diet” for the rest of the time. Many of his study subjects have noticed improvements in organ health – even in some cases causing pancreatic genes that are normally activated during embryonic/fetal development to trigger the regeneration of pancreatic islet cells that can then make normal levels of insulin. He stresses that it is absolutely essential that any person wanting to treat any type of diabetes with his protocol do so only under the strict supervision of a doctor. It is essential to be very careful with diabetes medication as to make a mistake could result in hypoglycemia or, rarely, death.

The benefits of using a protocol that allows you to eat every day, albeit a reduced amount, is that feelings of deprivation are less likely to result in overeating on non-restricted days. So, why would a seemingly simple idea like reducing food intake have so many health benefits? There are several factors, mostly to do with how our bodies are designed to work. The idea of having three meals a day is a fairly modern development and has a lot to do with social interaction and conventional family and community behaviors. Further back in our history, it was more normal to eat either only when hungry or when there was food available, which was not a “given”. There were no grocery stores in our earliest history – people would eat when there had been a kill or when roots or other vegetable foods were available. When we deprive ourselves of the normal amount of food, our bodies become remarkably adept at sharpening mental and physical abilities and being ready to find the next source of food. So we can feel energetic and very focused with a lower or non-existent calorie intake. To quote Thomas Reuter in a Business Insider article, “It makes sense that the brain needs to be functioning very well when an individual is in a fasted state because it’s in that state that they have to figure out how to find food. They also have to be able to expend a lot of energy. Individuals whose brains were not functioning well while fasting would not be able to compete and thrive.”

Also, periodic fasting can make it more likely that the body will burn fat and enter ketosis, “…a metabolic state in which some of the body’s energy supply comes from ketone bodies in the blood, in contrast to a state of glycolysis in which blood glucose provides energy. Generally, ketosis occurs when the body is metabolizing fat at a high rate and converting fatty acids into ketones.” (Wikipedia).

One of the reasons for this sharpened mental clarity is that hunger can give a sense of focus when ketosis triggers release of a molecule called BDNF, which is known to strengthen neurons and brain connection linked to learning and memory. Blood samples taken from people who are fasting 12-24 hours show the subjects have entered a state of ketosis. A device resembling a blood glucose meter can measure ketones. In ketosis, the body gets more energy from fat as it improves at using fat as fuel. Mental benefits include improvements to mood and memory and even to the progression of demyelinating diseases like Alzheimer’s.

Just as with learning anything new, it takes a while to become adept at intermittent fasting. It’s not as easy as it sounds to just stop doing something as essential as eating. It can be hard to deal with the mental and physical challenges like cravings, headaches etc. Even knowing the plentiful health benefits, it takes practice and repetition to improve to the point where it becomes second nature and the first few attempts might be quite uncomfortable due to the metabolic adjustment and to a mild detoxification that happens as undesirable things are flushed from the body.

As fasting is embodied in several ancient religious traditions, it seems to be that its wisdom is ingrained in our common history. Modern research backs this wisdom up with blood test results and tangible health benefits. Fasting is shown to be very effective in weight loss and anti-aging therapy as well as showing marked improvements in immune system function. Researchers have recorded visible signs that organs are being renewed and regenerated during certain types of fasts. With so many benefits, it would be a useful addition to any health regimen, but as human bodies and minds vary widely from person to person, anyone considering adopting any kind of fasting should only do so with the agreement of and supervision by a physician who is trained in this area.

For more information on this topic check out Kevin Loria’s article here.

To learn about nutritional fasting, find out why fasting through starvation isn’t the safest way. You can find our three-part article here.