For years I have told my clients to eat every 3-4 hours. That strategy-combined with wise food choices, a smart exercise program and effective coaching-has helped my clients loose weight and drop pounds of body fat.
Proponents of Intermittent Fast (IF), on the other hand, reject the idea of eating so often.
Many say they’ve gotten healthier and leaner, faster, by deliberately skipping meals and sometimes going entire days without eating.
As I started to read the research on intermittent fasting, I was intrigued and thought I’d give it a try. The results? I lost 10lbs in the first six weeks and maintained that weight loss for the six months I’ve continued with IF. I had more energy, better focus and improved mood. I was also able to be less “strict” and more flexible with my food choices.
So what is IF, exactly? Simply stated, it’s the cycling between periods of fasting and eating. It’s currently a very popular method to lose weight and improve health. Not only was it the “trendiest” weight loss search term in 2019, it was also prominently featured in a review in The New England Journal of Medicine.
IF can provide significant health benefits if it is done right, including loss of excess weight, loss of body fat, lowered blood insulin and sugar levels, improved mental clarity and concentration, increase energy, improved blood cholesterol profile, reduced inflammation, and longer life. Plus, it can save you time and money.
What is IF?
Fast is the voluntary withholding of food for spiritual, health, or other reasons. It’s done by someone who is not underweight and this has enough stored body fat to live off. IF done eight should not cause suffering.
Food is easily available, but you choose not to eat it. This can be for any period of time, from a few hours up to a few days or-with medical supervision-even a week or more. You may begin a fast at any time of your choosing, and you may end a fast at will, too. You can start or stop a fast for any reason or no reason at all.
Fasting has no standard duration, as it is merely the absence of eating. Anytime you are not eating, you are intermittently fasting. For example, you may fast between dinner and breakfast the next day, a period of approximately 12-14 hours. In that sense, intermittent fasting should be considered a part of everyday life.
How to Intermittent Fast
Intermittent fasting offers plenty of flexibility. You can fast for as long or short as you like, but fasts longer than a few days may require medical supervision.
Here are some popular regimens. Generally, shorter fasts are done more frequently.
This way of doing intermittent fasting involves daily fasting for 16 hours. Sometimes this is also referred to as an 8-hour eating ‘window’. You eat all your meals within an 8-hour time period and fast for the remaining 16 hours. Generally, this is done daily or almost daily.
For example, you may eat all your meals within the time period of 11:00 am and 7:00 pm. Generally, this means skipping breakfast, but some people prefer to skip dinner instead. Typically this involves eating either two or three meals within this 8-hour period.
This involves a 4-hour eating window and a 20-hour fast. For example, you might eat between 2:00 pm and 6:00 pm every day and fast for the other 20 hours. Generally, this would involve eating either one meal or two smaller meals within this period.
Longer fasts (>24 hours)
This way of doing intermittent fasting involves fasting from dinner to dinner (or lunch to lunch). If you eat dinner on day 1, you would skip the next day’s breakfast and lunch and eat dinner again on day 2. This means that you are still eating daily, but only once during that day. This would generally be done two to three times per week.
This is the version of intermittent fasting that has the most scientific support, as most studies on intermittent fasting has featured similar advice.
5:2 involves five regular eating days and two fasting days. However, on these two fasting days, you are allowed to eat 500 calories on each day. These calories can be consumed at any time during the day – either spread throughout the day or as a single meal.
Another related approach to 5:2 is to have “fasting” days with 500 calories not just twice a week, but every other day.
This involves fasting for the entire day. For example, if you eat dinner on day 1, you would fast for all of day 2 and not eat again until breakfast on day 3. This is generally 36 hours of fasting. This might provide a more powerful weight loss benefit and may help avoid the temptation to overeat dinner on day 2.
The first rule of extended fasts is to always check with your health care provider to ensure you are not at risk for fasting complications.
Generally for fasts greater than 48 hours, I recommend a general multivitamin to avoid micronutrient deficiency
Intermittent fasting FAQ
What are the big “takeaways”?
- Trial fasting is a great way to practice managing hunger. This is an essential skill for anyone who wants to get in shape and stay healthy and fit.
- More regular fasting isn’t objectively better for losing body fat. While my IF worked quite well, the intermittent fasting approach (bigger meals, less frequently) didn’t help me lose fat any faster or better than a more conventional diet approach (smaller meals, more frequently) might have.
- More regular fasting did make it easier to maintain a lower body fat percentage. Intermittent fasting isn’t easy. However, I did find that using this approach made it easier for me to maintain a lower body weight and a lower body fat percentage vs. more conventional diets.
- Intermittent fasting can work but it’s not for everyone, nor does it need to be. In the end, IF is just one approach, among many effective ones, for improving health, performance, and body composition.
So intermittent fasting is good, but not necessary?
Intermittent fasting can be helpful for in-shape people (who ideally have a healthy and sane relationship with food) who want to get lean without following conventional bodybuilding diets, or for anyone who needs to learn the difference between body hunger and mental hunger. (And for the latter, I only recommend the Trial Fast.)
It’s a helpful tool and one I’ll continue to use. But it’s not the end-all, be-all of nutrition or fitness.
People have been getting in awesome shape — and staying in awesome shape — for decades without the use of intermittent fasting.
How are IF and “grazing” similar?
Successful nutrition plans, whether they use smaller, more frequent meals (grazing) or larger, less frequent meals (fasting) all share a few features.
- Controlling energy intake. When we consume less energy (i.e. calories) than we burn, we lose weight (and, ideally, most of that is body fat). Whether you take in less energy by eating frequent small meals or infrequent larger meals is up to you.
- Focusing on food quality. Fresh, unprocessed, nutrient-dense food is a must, regardless of which eating style you adopt.
- Regular exercise. Exercise is a critical part of the equation.
Once those three have been taken care of, it’s a matter of personal preference and lifestyle considerations.