by Monique Tello, MD, MPH Contributing Editor
There’s a ton of incredibly promising intermittent fasting (IF) research done on fat rats. They lose weight, their blood pressure, cholesterol, and blood sugars improve… but they’re rats. Studies in humans, almost across the board, have shown that IF is safe and incredibly effective, but really no more effective than any other diet. In addition, many people find it difficult to fast.
But a growing body of research suggests that the timing of the fast is key, and can make IF a more realistic, sustainable, and effective approach for weight loss, as well as for diabetes prevention.
New research is suggesting that not all IF approaches are the same, and some are actually very reasonable, effective, and sustainable, especially when combined with a nutritious plant-based diet. So I’m prepared to take my lumps on this one (and even revise my prior post).
We have evolved to be in sync with the day/night cycle, i.e., a circadian rhythm. Our metabolism has adapted to daytime food, nighttime sleep. Nighttime eating is well associated with a higher risk of obesity, as well as diabetes.
Based on this, researchers from the University of Alabama conducted a study with a small group of obese men with prediabetes. They compared a form of intermittent fasting called “early time-restricted feeding,” where all meals were fit into an early eight-hour period of the day (7 am to 3 pm), or spread out over 12 hours (between 7 am and 7 pm). Both groups maintained their weight (did not gain or lose) but after five weeks, the eight-hours group had dramatically lower insulin levels and significantly improved insulin sensitivity, as well as significantly lower blood pressure. The best part? The eight-hours group also had significantly decreased appetite. They weren’t starving.
Just changing the timing of meals, by eating earlier in the day and extending the overnight fast, significantly benefited metabolism even in people who didn’t lose a single pound.
4 ways to use this information for better health
- Avoid sugars and refined grains. Instead, eat fruits, vegetables, beans, lentils, whole grains, lean proteins, and healthy fats (a sensible, plant-based, Mediterranean-style diet).
- Let your body burn fat between meals. Don’t snack. Be active throughout your day. Build muscle tone.
- Consider a simple form of intermittent fasting. Limit the hours of the day when you eat, and for best effect, make it earlier in the day (between 7 am to 3 pm, or even 10 am to 6 pm, but definitely not in the evening before bed).
- Avoid snacking or eating at nighttime, all the time.