It's no surprise that the low-carb, high-fat keto diet [1] and intermittent fasting [2] are the most popular diets of 2018 [3]. Both approaches have helped people lose weight [4] and improve their health, but according to obesity medicine physician and scientist Fatima Cody Stanford [5], MD, MPH, they aren't sustainable for long-term weight loss.
"When I prescribe things to patients, I like for them to be scientifically sound, ,eaning there's been a study done that's been done well," Dr. Stanford told POPSUGAR. Specifically, Dr. Stanford looks for studies that show long-term benefits when it comes the keto diet and intermittent fasting.
"When we look at the ketogenic diet, the research or the literature that's been done long-term really points to the ketogenic diet being excellent for patients that have seizure disorders or refractory seizure disorders," Dr. Stanford explained. Experts have also found that people with type 2 diabetes benefit from following the keto diet [6], because it lowers blood sugar and insulin levels and enables their bodies to use fat as the main source of energy.
While the keto diet has been proven effective for people with specific medical issues, "With regards to long-term benefits for weight and weight regulation, the studies have not been supportive," Dr. Stanford said. Although the keto diet may work for some in the long-term, Dr. Stanford said to consider whether or not you'll be able to (or want to) sustain it for five, 10, 15, or even 20 years.
"When we flip over to intermittent fasting, there are better studies that have been done long-term," she explained. There are a variety of ways to follow intermittent fasting [8], with 12:12 (you eat in a 12-hour window, and fast for 12 hours [9]) considered to be the easiest. While intermittent fasting beats keto on long-term sustainability, Dr. Stanford said, "Overall, there's a limited population that's able to really conform to intermittent fasting, or IF, over the long-term."
This doesn't mean that IF and keto won't work to help you initially begin to lose weight. But if your goal is long-term (we're talking longer than a few months) weight loss, Dr. Stanford advised finding a way of eating that you can commit for years to come. This will look different for everyone, but Dr. Stanford recommends beginning to eat lean proteins, whole grains, vegetables, and fruits to help you achieve your goals.