Fasting, the exercise of going prolonged periods of time without food, has been practiced in many cultures for centuries as a way to restore clear thinking and optimal body function, as well as connect with one’s spirituality. Lately, it’s been touted as the newest and best method for weight loss.
The longest fast on record is 382 days long, and was done by an obese man from Scotland that started his fast at 456 lbs. back in the 1960’s. He was medically supervised and supplemented with vitamins and minerals. Usually, the longest people can fast before death is about 30-40 days. This type of extreme fasting does have its benefits, but it also has consequences, and I don’t recommend you try this at home!
For people that really need to fast, the most significant benefits occur with 4 full days of fasting. Fasting less than 4 days still offers benefit, but not to the fullest extent possible. Fasting longer than 4 days can have weight loss benefits, but it is not necessary for optimal immune system function or resting the digestive system.
One type of fasting that offers benefits and life balance with the least amount of risk is intermittent fasting. Intermittent fasting starts with a reachable period of time when a person does not consume food. For example, to start, a person might go 10-12 hours each day without food. This is relatively easy when done overnight. It matters very little what time the last meal of the day is as long as the first meal of the next day is 10-12 hours later. Gradually, the period of fasting increases up to 16-20 hours.
The meals consumed during eating hours should be nutrient dense so that nutrition quality is not compromised leading to an increased risk of deficiencies. Meals should contain clean proteins, whole fruits and vegetables, whole grains, and plant-based fats. Also, meal portions should be “standard” in portion size. In other words, don’t make portions larger than you normally would eat to make up for having fewer meals in a day. But also, be certain to eat enough as a calorie intake that is too low will send the body into starvation mode. Keep in mind, too, that reduced calorie intake should be followed by reduced calorie expenditure. It’s sensible to lighten workouts to avoid injury and complete exhaustion.
Over time, people often notice improved cognitive function, sleep habits, and eating awareness. Most individuals also notice moderate to significant weight loss. The other health benefits such as improved insulin sensitivity and reduced risk of heart disease occur at the cellular level where adaptive cellular stress response and signaling pathways enhance mitochondrial health and DNA repair. If you have any kind of health concern, consider intermittent fasting as a way to improve your health.
People with health conditions or chronic diseases should fast only with the guidance of a doctor or dietitian who can help design the best approach. The fasting protocol can be modified to help reach specific health goals. For more information, contact Kari Collett, RDN, LDN, CLT at A to Zinc Nutrition.