Initial human studies that compared fasting every other day to eating less every day showed that both worked about equally for weight loss, though people struggled with the fasting days. So I had written off IF as no better or worse than simply eating less, only far more uncomfortable. My advice was to just stick with the sensible, plant-based, Mediterranean-style diet.
Conversely, a 2013 study completed by researchers at Washington University School of Medicine, presented the exact opposite, showing increased reactions in receptors on the tongue, when participants were given artificial sweeteners. Their study concluded that if the receptors are capable of detecting sweetness, even though calories aren’t present, a hormonal response (insulin release) is likely.
Since all of your hormones are so deeply interconnected, when one hormone is thrown off balance, the rest are also negatively impacted. It’s like a domino effect. As the “messengers” that regulate nearly every function in your body — from energy production to digestion, metabolism, and blood pressure — you don’t want to disrupt their natural rhythm.
Amy Shah, MD, is double board-certified doctor who received her medical training from Cornell, Harvard and Columbia Universities. She has a thriving medical practice in the Phoenix area, where she sees more than 5,000 patients each year. In 2015, Dr. Shah was named one of the “Top 100 Women in Wellness to Watch” by MindBodyGreen and was a guest on the Dr. Oz show.
People fast for so many reasons; some fast because they're trying to lose weight while others fast to improve medical conditions such as diabetes and high blood pressure. The science behind intermittent fasting has slowly been piling up, too, with research showing that participants of intermittent fasting experience a reduction in weight and inflammation and improvement in insulin sensitivities.
Whichever option you choose, there's enough evidence to show that intermittent fasting has many health benefits. Dr. Palanisamy sums it up best by saying, "The final caveat is that some fasting is better than none. So if having a regular or even bulletproof coffee is the only way that you can stick with the practice of intermittent fasting, then it's probably worth it."
With this information in hand, you should know exactly how to schedule meals when starting an intermittent fasting plan. And while it might seem complicated at first, once you get into the habit of fasting, it will feel like second nature and fit pretty seamlessly into your days. Just remember to always start slow and gradually work up to more advanced plans.
16-hour fast (aka 16:8): The most popular type of intermittent fast, the 16-hour fast encourages you to eat all of your meals in an 8-hour window, such as noon to 8pm. To activate the full benefits of intermittent fasting, try an 18-hour fast, once you’ve adapted to 16 hours. This would mean eating between noon and 6pm or between 2pm and 8pm. Simply avoid eating after dinner, and skip breakfast in the morning. Limit carbs to dinner.
Eat normally for five days of the week, taking in fewer than 600 calories on the remaining two days; fasting days should be non consecutive. This is a slightly less arduous variation of the every-other-day fasting plan, but it also puts you in the fasted state for significantly less time. Consider using this particular intermittent fasting schedule as a stepping stone to something more advanced.
In animal studies, after two weeks of intermittent fasting, female rats stopped having menstrual cycles and their ovaries shrunk while experiencing more insomnia than their male counterparts (though the male rats did experience lower testosterone production). (6) Unfortunately, there are very few human studies looking at the differences between intermittent fasting for men and women, but the animal studies confirm our suspicion: Intermittent fasting for long periods of time can sometimes throw off a woman’s hormonal balance, cause fertility problems and exacerbate eating disorders like anorexia, bulimia and binge eating disorder.
If you want to lose weight, you need to be burning more calories than you consume. A good diet will help reduce your calorie intake. Working out will increase your calorie burn. But while each of these is a step in the right direction, why not approach the problem from both ends? Intermittent fasting empowers you cut down on the influx of calories while also training your body to become better and more efficient at using the calories stored in fat cells. The end result is a quicker path to a healthier you. You could even call it the “fast” track to weight loss success.
Even though this plan is advanced, it's very simple. Don't eat anything every other day. This is the most intense form of fasting but can produce amazing results. Every other day, eat healthy fats, clean meat sources, vegetables, and some fruit, and then on your fasting days, you can consume water, herbal tea, and moderate amounts of black coffee or tea.
Every diet plan that has ever produced results is, at its heart, a strategy for lowering calorie intake. All-fat, no-fat, reduced-carbs, gluten-free, paleo… they may all take different approaches to weight loss, but they all have the same result. By limiting food intake, or even just limiting food options, these diets reduce our calorie consumption. And when calorie intake drops below calorie burn, that’s when we start to drop the pounds.
I was very curious about this, so I asked the opinion of metabolic expert Dr. Deborah Wexler, Director of the Massachusetts General Hospital Diabetes Center and associate professor at Harvard Medical School. Here is what she told me. “There is evidence to suggest that the circadian rhythm fasting approach, where meals are restricted to an eight to 10-hour period of the daytime, is effective,” she confirmed, though generally she recommends that people “use an eating approach that works for them and is sustainable to them.”
Intermittent fasting isn't a regimen built around limiting calories (although it's likely that your calorie intake will be restricted naturally since you're going a period of time without eating), but it can promote weight loss in a big way. Fasting gives your metabolism an overhaul. It works on the same principles as a ketogenic diet. By restricting food (and carbohydrates), you'll switch your body from burning glucose for energy to burning stored body fat.
You’re consuming less food and thus spending less money. Rather than overeating to put on 1 pound of muscle and 4 pounds of fat in a week or two, you’re aiming to eat exactly enough to put on 1 pound of muscle without adding much fat on top of it. Yeah, it’s a delicate balance, but there’s far less swing involved. You are just slowly, steadily, and consistently building muscle and strength over many months.