DIETING TRENDS come and go. They always have. Since humans began to study and then manipulate our physiology, health and fitness trends have emerged, usually promising revolutionary benefits, only to fade into oblivion once they face the full force of scientific scrutiny. Few emerge from this process unscathed. Occasionally though, some of these trends are legit.
Fasting is one such trend, though, in fact, it’s a natural way of life that’s been around since the dawn of humanity, with a purpose that’s integral to your body’s cycle and function, a fact that perhaps explains its effectiveness. You’ve likely heard word-of-mouth testimony on the benefits of fasting from someone who’s tried it, or from someone who knows someone who’s tried it—hardly convincing evidence, we know. But take it from us, there can be real benefits to fasting, which exists in the small space where scientific research and fitness guru reinterpretation meet.
If you’re considering giving fasting a try, it’s important that you first have all the information necessary to make the right decision. To assist, this is everything you need to know about fasting, from its benefits to its dangers.
What is fasting?
Technically, regardless of whether or not you’re considering taking up fasting for its fitness benefits, you already fast every day. Fasting refers to the—typically overnight—period which delineates your last meal of the day from your first meal of the next day. This is a crucial component of the body’s daily cycle, and it’s a process that has developed through habitual human actions over thousands of years.
Believe it or not, this a supremely natural routine. With many of the material issues of the first world solved, including hunger and access to food, humans have become accustomed to ingesting three hearty meals a day and treating themselves to snacks throughout. Fasting takes us back to our roots, to when our ancestors were forced to fast due to scarcity of food. In this time, our cells learned to function with irregular caloric intakes.
Regular fasting becomes a purposeful dieting choice when you intentionally abstain from eating. This usually involves limiting caloric intake for an extended period of time, to put the body into a fasted state. Low-calorie fluids like water are the exception to this rule though, as they can still be consumed.
What’s the difference between intermittent fasting and regular fasting?
As we discussed above, everyone fasts. Intermittent fasting can be differentiated from a standard fast in that it’s intentional. Intermittent fasting involves drawing out the fasting period by alternating between periods of fasting and eating. A typical intermittent fasting plan is to go without food for 16 hours, and then indulge for eight.
What are the benefits to fasting?
Fasting plays an important role in the body’s metabolism and the regulation of hormones. During fasting, fatty acids are broken down and converted to energy. Waste is also able to be broken down and safely evacuated.
Most of that stuff naturally occurs during an overnight fast, however, intentional intermittent fasting has a variety of other effects. One study found that intermittent fasting can lower insulin levels, and other studies have shown the practice can improve cholesterol and glucose levels, lower blood pressure and even improve longevity.
Of course, fasting is also a means of achieving weight loss. While intermittent fasting doesn’t explicitly call for lower caloric intake, the smaller timeframes for eating typically result in less calories being consumed and lower levels of hunger. In turn, the weight loss caused by intermittent fasting provides an array of further benefits.
How does fasting impact fitness?
Fasting can have a significant impact on fitness, and it’s important to weigh the outcomes before partaking in the diet. Fasting is a means of achieving lasting weight loss, improving cardiovascular fitness, and reducing the body’s fat content. Although, it will also commonly cause losses to muscle mass and composition. Smaller muscles are often a necessary evil when it comes to losing weight, though, so if you’re prioritising weight loss over muscle gain, this information shouldn’t deter you from fasting.
It’s also important to manage the intensity of your workouts when you’re in a fasted state. You can still work out while fasting, and exercising on an empty stomach will have its own benefits, but your intensity will need to be adjusted, as you simply can’t push as hard when your body has less available energy to burn. If you experience any light-headedness or dizziness while working out in a fasted state, you should stop immediately and have something to eat and drink.
How long should you fast for?
There is very little consensus on this subject. Ultimately, the answer will depend on your unique physiological composition, but there are a few popular styles of fasting, all with different timeframes. Which one you choose to adopt will depend on your lifestyle and goals.
The most popular and achievable form of fasting, intermittent or time-restricted fasting, places shorter restrictions on when you can and can’t eat. The most common structure is the 16:8 method. This involves fasting for 16 hours of the day and eating for eight. Under this format, you might abstain from eating until 12pm, when you break your fast and begin an eating period which lasts until a final meal at 8pm. This structure is the easiest to adopt, but don’t feel hampered by arbitrary time restrictions. The 16-hour no food period can begin and end at any time of the day.
Alternate day fasting
As one of the more drastic forms of fasting, alternate day fasting typically involves alternating between fast days and feast days. No, fast days do not require you to not consume any calories at all, but as minimal an amount as possible. The following day will see you resume your typical eating activites, eating practically as much as you want.
Alternate day fasting is far more difficult to get into, it takes quite a commitment to maintain this diet for longer than a few days.
Whole day fasting
Similar to alternate day fasting, whole day fasting requires participants to eat as few calories as possible on specific days, often amounting to just 500 calories per day. The 5:2 schedule is common here, calling for five days of regular caloric intake, separated by two days of minimal intake.
Are there dangers to fasting?
As any Snickers advertisement will tell you, you’re not you when you’re hungry. Irritability is one of the biggest negative side effects of fasting, as the brain and body function differently on an empty stomach, often resulting in a less jovial mood.
Psychologically, there are concerns that fasting can lead to the development of eating disorders, but this hasn’t been clinically proven, and most diets present this risk. Apart from that, fasting has cleared the charges of causing constipation, diarrhoea, nausea, and chronic fatigue. However, fasting can result in lower energy levels, so if you’re gearing up for a big day at work or a particularly taxing workout, we wouldn’t advise a fasting session.