Intermittent fasting’s benefits go beyond weight loss: 5 benefits and 5 ways to get started
Research is showing numerous benefits to the popular regimen. But it's important to have a well-thought-out approach, writes a Philadelphia physician.
Intermittent fasting — the practice of strictly limiting the hours when one eats — keeps getting more popular. For years, obesity scientists and physicians collected data to understand the benefits of this eating pattern, and that work is bearing interesting results.
A recent review article published in the prestigious New England Journal of Medicine compiled the literature about the benefits of intermittent fasting. Most interesting, these benefits seem to go well beyond weight loss. Intermittent fasting can reverse insulin resistance in patients with prediabetes or type 2 diabetes.
Intermittent fasting can improve multiple indicators of heart health in healthy and obese people, including blood pressure, resting heart rate, levels of cholesterol, and triglycerides.
Studies performed in overweight women showed a reduction in abdominal fat with lower waist circumference. It is important to note that intermittent fasting is no better or worse than other calorie-restricted diets in terms of weight loss, but it offers dieters another option.
There are links to improvements in verbal memory and cognition. One clinical trial showed two years of daily caloric restriction led to improvement in memory. Another study in overweight adults with cognitive impairment showed that 12 months of caloric restriction led to improvements in verbal memory, executive functioning, and global cognition. While there are a lot of factors that could influence these results, it’s certainly worth more study.
In animal studies, caloric restriction has been shown to affect aging, result in an increase in life span of rats and mice. But bear in mind that animal studies often do not translate into human results, and it’s a lot easier to restrict the intake of a rodent than a person.
For anyone interested in starting intermittent fasting, here are five suggestions:
Get a health-care support system. Either a registered dietitian or physician familiar with nutrition can ensure the new eating plan is carried out in a safe, healthy manner. If you are eating fewer meals, it is especially important to be sure they are packed with the macronutrients you need.
Choose a type of intermittent fasting that fits into your lifestyle. There are three general methods: alternate day (eating normally one day and then not at all the next day); 5:2 (eating normally five days a week and then restricting two days a week to a very low level of calories; daily time-restricted (choosing a six- to 10-hour window for eating and fasting the rest of the time). As long as you don’t make the mistake of gorging yourself during the permitted eating times, it shouldn’t matter which you choose.
These diets should be initiated gradually, slowly reducing the time window during which food is consumed daily, and for those doing the 5:2 approach, gradually cutting calories down to no fewer than 500.
Expect increased hunger, irritability, and reduced ability to concentrate initially. These should improve — depending on the individual, it might take days or weeks.
Last, don’t let intermittent fasting affect your mental health. It’s definitely not recommended for people with a history of eating disorders or obsessive behavior in the pursuit of a healthy diet, for children and teens, or for people with conditions like diabetes unless they are closely monitored by their doctors.
Keerthi Shah is a gastrointestinal fellow at Temple University. You can follow her on Twitter at @KeerthiShahDO or Instagram at @digestivedoc.