Should I Be Fasting?

Intermittent fasting and time restricted eating (TRE) are a hot topic in the health and fitness space. TRE is when you only eat between certain hours of the day- maybe that’s 9am-7pm- and you don’t eat outside of that time frame, and intermittent fasting is the time in between when you aren’t eating. There are many claims that by simply eating within a certain window, weight loss will occur. But is this really the case?

Like all “diets”, if the end result is weight loss, then it’s likely due to a calorie deficit. That being said, some diets make it much easier to eat less calories than others. For example, the “if it fits your macros” style of dieting says that you can eat literally anything, as long as it stays within your macronutrient and calorie targets. It is true that this can lead to weight loss if you remain in a calorie deficit; however, eating calorie dense, yet not so filling processed foods makes it very difficult to stay within those calorie ranges. On the other hand, more whole foods based diets such as Paleo or Mediterranean include highly filling yet low calorie vegetables, meats, and fruits. This makes it easier to stay in a calorie deficit. We see the "calories in vs calories out" phenomenon over short periods of time. For long term results, however, there are many other factors that play a role in weight management such as hormonal health, sleep quality, metabolic health, etc.

As expected, it seems that the same thing holds true with TRE. Based on the research, people in a calorie deficit applying TRE had similar results to those in a calorie deficit without TRE. The calorie restriction is what promotes weight loss, not the time of day or TRE.

With that said, it’s important to look at how TRE can be used as an effective tool for weight management. If there are less hours in the day devoted to eating, less calories will likely be consumed. For example, this can be helpful for those who struggle with late night binges. The light use of TRE can promote healthy boundaries with food and eating times, and detaching from those late night cravings!

At the end of the day, fasting and TRE are not necessary for weight loss. Weight loss really only happens in a calorie deficit, and there are many different diets and strategies people use to achieve this deficit- TRE is one of them. As always, it all depends on the individual. While TRE might be an effective tool, if it feels too restrictive or problematic for you, its not something you should be forcing upon yourself in the name of weight loss. We also have to consider the fact that not everyone should have the goal of weight loss, and in some cases calorie restriction is NOT what is best for improving health status. Those who have developed a slow metabolism and might be dealing with hormonal imbalances or other underlying issues should not simply reduce calories to lose weight. Its important to work with someone who can help you identify the root cause of your symptoms (like weight gain)!

Source used:

A. Aragon. Calorie Restriction With or Without Time-Restricted Eating in Weight Loss. Alan Aragon’s Research Review. April 2022,