Carrying excess body fat (particularly belly fat) increases risk for metabolic syndrome (see page 4) and diseases that include cardiovascular disease, type 2 diabetes, and cancer. Intermittent fasting is currently a popular weight loss method. Evidence suggests it can be as effective as traditional calorie cutting, although it is not appropriate for everyone. Could this eating style be for you?
Think “Fast.” Intermittent fasting involves eating only during specific times of the day or
➧ Ask your doctor. Talk to a healthcare provider before starting an intermittent fasting regimen, particularly regarding any medications you are taking.
➧ Find what works for you. Consider if a fasting regimen fits with your lifestyle, schedule, and medication routine. If you feel unwell when you skip meals, fasting is not for you.
➧ Hydrate. Make sure to drink plenty of non-caloric beverages (like water or unsweetened coffee or tea) during periods of fasting.
➧ Cut calories. Don’t go crazy during eating periods! Binging after a fast will not help with weight loss.
➧ Make nutritious choices. Cutting food intake means making each bite more nutritious! Choose fruits, vegetables, legumes, whole grains, fat-free and nonfat dairy, and lean proteins whenever you eat.
➧ Keep moving. Weight loss can lead to muscle loss if not done right. Work those muscles to help maintain lean body mass.
Health Benefits. Reducing the number of calories we take in leads to weight loss, which has clear health benefits in individuals who have excess body fat. Fast periods have the potential to automatically restrict the number of calories we take in. Whether fasting regimens are superior to the more traditional continuous calorie restriction (cutting calories) remains unclear.
Most studies have looked only at the short-term benefits of intermittent fasting (less than 12 weeks). There is little information on potential long-term benefits (or harms).
“One study looking at intermittent fasting versus caloric restriction over a one year period found intermittent fasting was more beneficial than continuous caloric restriction on markers of metabolic health in the short term,” says Sai Krupa Das, a senior scientist on the Energy Metabolism Team and a professor at the Friedman School, “but the two diets led to the same weigh and health improvements over the long term.”
It has been suggested that intermittent fasting helps control hunger and desire to eat, but a recent systematic review and meta-analysis concluded this is not the case.
“Work is underway to rigorously look at long-term health and aging benefits of intermittent fasting in humans,” says Das, “but it will be about 10 years before we have really strong information.”
Health Concerns. “Fasting may not be for everyone,” says Das. “For example, if you are on medications that need to be taken at a particular time and with meals to be effective, the fasting routine may compromise those requirements and the effectiveness of the medications. We need to look at the safety of intermittent fasting throughout the lifecycle and at different weights, especially for people on various medications.” For those who feel unwell when they miss meals, fasting is not a good choice.
What to Do. If you are interested in trying an intermittent fasting regimen, check with your healthcare provider first, especially with regard to medications. It’s important to meet your nutrient needs on whatever calorie-cutting plan you choose, so making healthy dietary choices during eating periods is essential. For people who struggle to cut calories across-the-board, only needing to do so intermittently might be a more feasible option. “The important thing is to find what works for you. Both intermittent fasting and continuous calorie restriction can lead to weight loss and benefit health if done correctly,” says Das.