Is Intermittent Fasting Actually Good for You?
Reviewed & Approved by Dr. Larry
While the definition of ‘intermittent fasting’ is still pretty subjective, dietitian and nutrition expert Allison Evanson defines intermittent fasting as: “The mini-fasts that we do every night” while we sleep. She suggests that by limiting your caloric intake to twelve hours or less and then fasting overnight and not consuming calories for at least twelve hours, you could be doing your body a favor. Does that mean that intermittent fasting can help you lose weight?
Research on fasting and its effects on health and weight loss have been a topic for years. But researchers have often found that when people fast within an 8-12 hour window of time and then are consuming healthy meals the rest of the time they’ve been shown to have:
- improved glucose control
- better metabolic markers
- improved body weight
When combining the intermittent fasting of roughly twelve-hour blocks of time spent not consuming calories with 12 hours spent consuming healthy meals consisting of a source of protein, a serving of vegetables, and a source of healthy fats; most people will feel healthier, more full and satisfied, and are more likely to succeed in their weight loss goals.
Allison says that these timeframes of intermittent fasting are not a strict eating schedule, but rather they provide you with a rough structure to know when your healthy eating times are.
There are many trendy diets that use intermittent fasting in an excessively restrictive sense, such as consuming fewer than 600 calories on alternating days, or on the weekends.
While that kind of intermittent fasting works in the sense that you’ll be dropping pounds due to the lower caloric intake, you’ll be more likely to binge-eat on unhealthy foods during non-fasting times, experience unhealthy and dramatic spikes and drops in blood sugar levels, and gain back the weight you lose on your fasting days.
Does intermittent fasting work for losing weight — yes; people are losing weight through healthy intermittent fasting like the kind Allison suggests, and they’re experiencing the overall long-term health benefits promised. But only when you intermittently fast healthily by combining it with Allison’s more realistic approach to intermittent fasting and healthier meals.
That means that starving yourself excessively and then eating unhealthily during your non-fasting times isn’t going to work for weight loss and it could do some damage to your health and glucose regulation.
For example, if you fast intermittently, then eat unhealthily, fast again and repeat, you aren’t going to lose weight. Fasting isn’t a magical solution to losing weight; it simply gives you a better framework for when you should stop eating for the day, like Allison suggests.
Does intermittent fasting work if you fast for longer than Allison’s suggested twelve hours? She says that the benefits of intermittent fasting for longer than twelve hours or less than eight aren’t as frequently observed in the research conducted so far.
Yes, fasting for longer than twelve hours and then consuming your normal intake of healthy calories could also be beneficial, but it’s also less likely that you’ll stick to it without starting to feel too hungry and over-eat unhealthy foods when your fasting period is over as a result. It’s more realistic to stay within the 8-12 hour intermittent fasting timeframes if you want it to work for you without feeling miserable.
By consuming calories from 8 a.m. to 8 p.m., 10 a.m. to 6 p.m., (or whatever timeframe works for you) and then fasting the remaining time at night, you can improve your health and promote weight loss. Time to swap out that midnight snack of ice cream for a glass of water!
Allison Evanson, MS, RD is the Registered Dietitian and follow-up coach for AffirmativHealth’s RE:Mind program, the Outpatient Dietitian at Sonoma Valley Hospital, and writer for putyourfoodtowork.com. Allison’s approach is to present healthy eating in a way that is realistic, sustainable, and enjoyable