Fasting can be good for you – but don’t make a meal of it
One of the most popular health trends today is intermittent fasting. As with any new dieting approach, there are many basic questions about intermittent fasting: what is it, does it work, and can anyone do it?
Well, to answer this, let’s start at the top, and understand what it is and what the research says.
Intermittent fasting is an eating pattern that cycles between periods of fasting and eating. It‘s promoted for fat and weight loss, longevity, enhanced cognitive ability, and improvements in markers such as blood sugar, cholesterol, and inflammation.
There are different types of intermittent fasting. Some of the most popular are:
• The 16:8 Method or Leangains Fasting Protocol. This is the most popular type of fasting routine. In this method, you fast for 16 consecutive hours, and eat during the remaining eight hours. This means that if you stop eating dinner at 20:00, you fast until 12:00 the following day.
• Alternate-day fasting or eat-stop-eat fasting. This involves complete fasting for 24-hour periods, similar to the length of Yom Kippur, for one to two days per week. The other five days incorporate normal eating routines.
• Modified Fasting or 5:2. This involves a fast day where individuals restrict their caloric intake to 25% of their normal daily caloric requirements for two non-consecutive days of the week – the other five days incorporate normal eating routines.
The only things you can have during total fasting hours are water, black tea, or black coffee (no milk or sugar).
Numerous changes occur in our body when we fast. When we eat, glucose and fat are used as the body’s main source of energy. Glucose is usually used first.
However, when glucose is not available to use as fuel, such as in a fasting state, the body switches to using fat as its main fuel source. This can then lead to “fat burning”.
Hormonal changes also occur during a fasting state like a drop in insulin, which increases the accessibility of fat stores, and an increase in growth hormone, which stimulates growth and cell regeneration.
Weight loss is by far the most studied benefit of intermittent fasting. Research is mixed as to whether intermittent fasting or a normal calorie-restrictive diet is more effective for weight loss. Some studies show that intermittent fasting results in less muscle loss and greater reduction in body fat.
It seems that the success of intermittent fasting can be due to it being easier to follow than a “normal” diet, resulting in increased compliance and sustainability.
Intermittent fasting doesn’t dictate what and how much you should be eating, but rather when you should be eating. However, people forget that creating a caloric deficit is still important, and mindfully eating a balanced diet still holds true. Being a glutton during non-fasting hours will limit its success.
Intermittent fasting is also in the spotlight for other potentially powerful benefits such as a reduced risk of developing diabetes due to reduced insulin levels, improved cardiac health by reducing blood pressure and LDL cholesterol (the unhealthy cholesterol). It also potentially increases longevity, though the studies have mostly been done on mice.
Research has also shown that intermittent fasting upregulates our antioxidant and anti-inflammatory pathways as a result of causing a mild stress response in our cells.
Based on the above information, intermittent fasting sounds great for everyone, right?
Unfortunately, it isn’t. While a lot of research has been done on its benefits, many of the studies to date have a variety of limiting factors. These range from the length and size of the study group, to testing on animals rather than humans.
Intermittent fasting is not a one-size-fits-all solution. It’s important to understand that choosing whether to do it also depends on your medical history, and your health goals.
Certain groups of people should not fast at all, or should do so under professional guidance, including:
– Pregnant or breastfeeding women, women with fertility or hormonal problems;
– People with a history of nutritional deficiencies or any form of disordered eating;
– People with advanced diabetes on insulin; and
– Anyone suffering from chronic diseases or on medication.
Though intermittent fasting can be beneficial, as always, it’s best to fast under the guidance of a dietitian as more conclusive research is needed, especially in the case of specific patient profiles.
Ask yourself what eating approach is most sustainable for you. If fasting results in imbalanced eating with extreme hunger, side effects, or poor compliance, then it’s not a balanced approach for you.
Learn what’s good for your health, and go with it.
Hilit Milner is a registered clinical dietitian who runs a private practice, works in a top private hospital, and has founded a wellness blog called ‘Sunrise by HM’. She views health holistically, starting from a cellular level and working her way out. She has an appetite for all things connected to nutrition, health, fitness, and their close relationship to mental well-being.