Intermittent Fasting: Good or Bad?

Intermittent fasting is trending in the health and fitness field. Some claims have been made that intermittent fasting could help with weight loss, manage blood pressure, blood sugar and cholesterol, and more. But is it really this amazing? Let's take a look at some researches.

Intermittent fasting is an eating pattern that involves alternating eating and fasting for a few weeks or a few months. Intermittent fasting is not considered as a “diet” since it isn’t about what to eat, but about when to eat it. Read this article and learn more about what intermittent fasting is.

The Good:

Theoretically speaking, intermittent fasting could help weight loss since it forces us to reduce the total calories we consume. Most studies on intermittent fasting find that it helps with weight loss, ranging from 2.5%-9.6%. More specifically, some studies found that the amount of weight lost following an alternate day fasting for 3 or 6 months was not significant compared to that lost via a typical low-calorie diet.

Intermittent fasting has also been found to affect insulin levels leading to some promising health benefits, but the research that suggests this is contradictory: several studies have shown that intermittent fasting could decrease fasting insulin and improve insulin sensitivity while others did not find a significant difference at all.

The Bad:

Although there could be some health benefits with intermittent fasting, the risk could be high as well. Malnutrition will be a leading risk of fasting since people are not getting enough calories and nutrients that they need from foods. So does nutrient deficiency. The food choice on non-fasting days will be very important.

People may also experience tiredness, hard to concentrate, fatigue, dehydration during fasting days due to insufficient energy intake. Some researches also revealed that people tend to eat more on non-fasting days after a period of fasting.

For people with diabetes, fasting along with the use of certain antidiabetic medications may lead to hypoglycemia, which could be fatal.

Although intermittent fasting has been a hot and popular topic in recent years, not much research has been done in this field. Most current studies are small with a short duration, and not well set-up with little regard for weight loss potential of obese versus lower weight adults. More studies are definitely needed especially since long term effects of fasting on circadian rhythms, hormones, and our organs are still not well known.

The Bottom Line:

Intermittent fasting is currently not a recommended treatment for weight loss and chronic disease management. Research is limited with small sample size, short duration, unrepresentative sample populations and various eating patterns. More studies will be needed to determine how it actually works, who it is best suited for, and long-term impacts. Intermittent fasting may be helpful for certain populations that we don’t yet know about, but it is not suitable for pregnant or breast-feeding women, people with diabetes (especially people that are taking insulin), people with eating disorders or have history of eating disorders, people are in risk of malnutrition, people that takes certain medications, and others.

Talk to your doctor or dietitian first before you start a diet like this, and let us help to guide you. If you are fasting for religious reasons, discuss this with your doctor to better adjust medications during the fasting period.