These days, you can’t throw a (proverbial) rock without hitting someone who’s tried one form of intermittent fasting (IF) or another. From the 16:8 regimen to the 5:2 model, it seems like no one is having breakfast these days. But who can blame them? With research crediting IF with everything from improving insulin sensitivity (1) and aiding with cellular repair (2) to reducing inflammation (3) (4) and slowing down the aging process (5), it’s become one of the most popular health trends of the past decades. And while its proponents will argue – and rightfully so – that fasting is not a trend but rather a way of healing the body that has existed in almost every single civilization for centuries, the truth of the matter is that most of us know very little about it and, as a result, are prone to going about it the wrong way.
With that in mind, we tapped Functional Medicine Practitioner Dr. Nasr Al-Jafari to understand the most common mistakes he’s seen patients make when embarking on intermittent fasting.
Probably the most common program most people follow is a variation on the 16:8 regimen, which involves fasting for 16 hours and consuming all of your daily food intake during an eight-hour window.
Whilst this may work well – certainly initially – some people plateau and often end up re-gaining at least some of the weight in the longer term. The issue here is very similar to that of the “calorie restriction” weight-loss trap that most people fall into when they embark on a regular diet.
When trying to fast intermittently, people will – often inadvertently – end up not consuming enough energy during the eating window and effectively calorie restricting. Whilst time-restricted feeding (or intermittent fasting) has proven to have many health benefits, one of the downsides can be a metabolic change in response to the calorie restriction. The body’s basal metabolic rate reduces to compensate for the fact that you are getting less energy, i.e. your metabolism slows down. This is also known as “starvation mode” for your body. In order for IF to be a long-lasting, beneficial way of living and eating, it is crucial to make sure that you do not end up eating fewer calories as a result of the reduced eating window.
The Problem With Skipping Breakfast
Another popular variation of time-restricted feeding is to skip breakfast. This is often because breakfast is the easiest meal to skip with respect to our current lifestyles. Whilst this may work well for some people, one needs to just bear in mind that the body is metabolically primed to eat during daylight hours. The old saying “eat breakfast like a king, lunch like a prince, and dinner like a pauper” actually has scientific basis.
The Other Problem With Skipping Breakfast
Similarly, because dinner is usually the most sociable meal, it often becomes the biggest meal of the day. Eating a large amount of food in the evening wreaks havoc on our hormones and can be especially disruptive for sleep quality. Good quality sleep is key for a healthier body.
Time-restricted feeding is not a free pass to snack during the feasting period. Constant grazing is unnatural. In fact, snacks were a 20th century invention to make more money for the food and drinks industry. To put it another way, when a farmer wants to fatten an animal for market, what do they do? They leave them to graze.
Fasting After Training
Another common question I get asked and a mistake people often make is in respect to training and exercise. Whilst training in a fasted state can be beneficial (for most people), fasting following training is not recommended. This comes down to our stress hormone, otherwise known as cortisol. In instances of fasts after training, cortisol will put the body into survival mode, during which it will work hard to hold on to fat.
Forgoing a More Holistic Approach
Intermittent fasting is not a magic wand. If other aspects of your lifestyle are out of balance – for example, sleep is disrupted and emotional stress is high – then IF is unlikely to help much.
Forgetting Other Healthy Eating Habits
Optimal nutrition is not just about when you eat; it is also about what you eat and how you eat. Intermittent fasting does not mean you can eat anything you want – read: processed foods and the like – so long as it is within a specific time window. It’s important to stick to a diverse nutritional intake of whole, fresh, unrefined, non-GMO foods. Similarly, instead of rushing meals, spend an adequate amount of time chewing your food, allowing for proper digestion.
Fearing More Extended Forms of IF
More benefit is derived from longer fasts. Whilst this may seem obvious, the benefit is not derived directly from the calorie deficit, but from the fact that the body is able to re-balance hormones more effectively (and reverse any insulin and leptin resistance) when given more time to do so. Also, from an energy standpoint, our livers carry a ready supply of glucose in the form of glycogen that usually lasts anywhere between 24 and 48 hours. Once glycogen runs out, the body is forced to use its fat reserves (a state otherwise known as ketosis).
Furthermore, studies of alternate daily fasting (ADF) show that the body’s basal metabolism is maintained over a prolonged period of time. Even with weight steadily decreasing, the resting metabolic rate remains virtually identical.
The same applies to more extended forms of fasting. The basal metabolism doesn’t shut down; it actually revs itself up. One study found that four consecutive days of fasting increased basal metabolism by 13 percent. Fundamentally, these changes do not occur with typical calorie-restriction diets.
Disclaimer: Please consult a doctor before performing any kind of diet change including intermittent fasting. This article is for informational purposes only.
Dr. Nas Al-Jafari BMBS BMedSci (Hons) MRCGP DPD DFSRH DOccMed is a Functional Medicine Practitioner, a Family Medicine Consultant, and the Medical Director at DNA Health Corp.