Intermittent fasting is all about limiting the time window in which you eat and extending periods when you abstain from food. You can seemingly choose any foods you like and eat how much you desire. That sounds almost too good to be true for a diet that should be healthy. Research shows that, under certain circumstances, it is in fact true and intermittent fasting can lower the risk of certain diseases.
As we discussed in the last article in this series, intermittent fasting is certainly an effective tool for weight loss. Losing weight can significantly reduce the risk of a variety of diseases. So, if you think you’re above your optimal weight, intermittent fasting can help.
Type 2 diabetes
Research shows that intermittent fasting has a positive impact on blood glucose by normalizing a crucial marker called HbA1c. It has also been shown to improve insulin resistance. These are both things that can lower the risk of type 2 diabetes or help manage it. One small study that compared non-obese men and women who followed an alternate-day fasting regimen showed improved insulin sensitivity in men but worsened blood sugar control in women. It’s good to keep in mind that intermittent fasting might not be beneficial for everyone but more on that later in the series.
All types of intermittent fasting, whether it’s time-restricted eating, whole-day fasting or alternate-day fasting, have been shown to improve the cardiovascular risk profile. Research says they can lower blood pressure, improve total and LDL cholesterol, triglycerides, and decrease weight and trunk fat.
We don’t have any direct data on intermittent fasting and cancer risk in humans. But we know that losing weight can reduce the risk of 13 different cancers that are linked to obesity. There is also evidence that intermittent fasting can improve a number of cancer risk biomarkers such as insulin, cytokines, and the inflammation-related molecules leptin and adiponectin. And we also have animal studies that suggest it may prevent cancer.
The most appealing claim about intermittent fasting is that it’s supposed to extend your life. There is research done on lab rats that showed that fasted rats lived up to 83% longer than regularly fed mice. Early human trials are also showing some promise. A 3-week alternate day fasting protocol showed a 2,7% increase in Sirtuin called SIRT3, which is a protein associated with longevity. It’s early to say if this can actually translate into a longer life but it’s certainly interesting.
A calorie deficit is the key
This is an impressive list of health benefits for a diet that doesn’t limit any specific food. But there’s a small catch. A recent study compared intermittent fasting with regular dieting that doesn’t impose time restrictions on eating. They found that when both of these approaches limit calories by the same amount, they both produce the same weight loss, same improvements in type 2 diabetes markers, and cardiovascular markers. This study also found that both of these approaches had similar numbers of people dropping out because they couldn’t follow through with the diet.
This is both good and bad news. The bad news is that there is nothing magical about intermittent fasting. It seems like as long as you create a calorie deficit and burn off more calories than you take in via food, you will experience all those health benefits. The good news is that you have a choice. If you prefer intermittent fasting as a way to reduce your calorie intake, go for it. If you’d rather eat regularly but reduce the size of your meals or choose less calorie-dense foods, that’s an option too as long as you achieve a calorie deficit.
The next question is: what if you aren’t interested in a calorie deficit? What if you want to use intermittent fasting for better endurance performance and recovery? The next article in the series will offer some answers.