Intermittent fasting is one of the buzziest trends in health and nutrition. It has been studied for its possible benefits in weight loss, boosting brain function, and promoting a longer life span. Defined as “an eating pattern that includes hours or days of no or minimal food consumption without deprivation of essential nutrients,” by the U.S. Department of Health and Human Services, it’s become a trendy eating plan that’s sparked curiosity for many.
So, which intermittent fasting (IF) plan is right for you and your lifestyle? First, you need to know about the different types of intermittent fasting plans that are out there.
5:2 Fasting: This method of IF requires that you eat your “normal” diet five days a week, while fasting two days a week. (According to the Mayo Clinic, a “fast” means consuming 500 calories or less per day).
16:8 or 14:10 Fasting: Also known as “daily time-restricted fasting,” this is one of the most popular IF plans. On a 16:8 plan, you eat “normally” within an eight hour window each day, while fasting for 16 hours. You get to choose your eating and fasting windows. For example, some people may only eat from 12 noon to 8 p.m.
Alternate day fasting (ADF): With this fasting plan, you eat “normally” one day and fast the next day (consuming only 500 calories or less), repeating throughout the week.
Keep in mind that longer periods of fasting, in 24, 36, 48, and 72 hour increments, are more dangerous and are not recommended, according to Johns Hopkins Medicine. In fact, your body may begin storing more fat as a starvation response.
If you’re brand new to IF, you’ll likely want to try out a few different methods to determine which one works best for you. Start slowly and ease yourself into a modified time restricted eating regimen, as recommended by Cleveland Clinic. So, for example, rather than jumping into a 16:8 method, try adopting a limited eating window, such as only eating from 8 a.m. to 6 p.m.
If you’re looking for flexibility, try 16:8 or 14:10 fasting
This method is a safer and more flexible option, especially if you’re just starting IF, according to Cleveland Clinic. With this method, you can set your fasting and eating windows and repeat throughout the week according to your personal preference.
If you’re trying to lose weight, try alternate day fasting
In one study, ADF participants saw significant reductions in weight and body mass index: over the course of two to three months, trial participants lost 3% to 7% of body weight. The participants’ total cholesterol, fat mass, systolic blood pressure and diastolic blood pressure were also altered. Overall, the study indicates that ADF is a feasible method for weight loss.
Additionally, a four-week ADF study found that body weight decreased by 4.5% while improving the fat-to-lean ratio, and concluded that ADF is a safe IF method for healthy, non-obese individuals.
If you are concerned about getting enough micro and macronutrients, try 5:2 fasting
One study found that, over a period of six weeks, participants were able to maintain a high protein, moderate fat, and low carbohydrate diet. While researchers noted that fiber intake was low, as well as some micronutrients, participants were overall getting sufficient nutrition.
IF might be risky for people with conditions and chronic diseases like diabetes, blood pressure issues and heart disease, according to Harvard Health Publishing. If you take certain medications for these conditions, IF could also have negative side effects. Additionally, IF is not safe for pregnant women, children, and people at risk for hypoglycemia.
Now that you’re familiar with the different types of IF, you can determine which intermittent fasting plan — if any — is right for you. While adopting one could help you reach your fitness goals, make sure you’re putting your overall health and wellbeing first.
Editor's note: The views expressed in this article are not intended to replace professional medical advice, diagnosis, or treatment.
About the author
Emily Shiffer is a former digital web producer for Men's Health and Prevention magazines, and she is currently a freelance writer specializing in health, nutrition, weight loss, and fitness. Her work has been published in digital and print formats for Women’s Health, Runner’s World, SELF, Health and more. She is based in Pennsylvania and loves all things antiques, music, and American history.