If you’ve read up on or taken an interest in intermittent fasting (IF) protocols, you may be familiar with the term ‘eating window’. An eating window is when you limit the amount of time you spend eating during a 24 hour day. On a normal day, if we are not careful, we can find ourselves eating from first thing in the morning up until as late as bedtime or even a cheeky midnight snack. This in itself keeps our digestive system active for a long period of time without much rest until we sleep.
Scientific research is now focusing more on the benefits of fasting on our health. By limiting our digestive activities to a set amount of time and only drinking water outside of that eating window, we are in effect giving our gut a rest, and it’s an opportunity for the body to work on other important processes aside from digestion. This doesn’t mean we eat less. We eat our meals closer together.
So what are the benefits of time-restricted eating? Time-restricted eating is in fact, considered a form of IF even if you eat the same number of meals as you would on a normal day. Some choose to skip breakfast; in this case, it’s important that you are getting lots of nutrients from the foods you do eat. Even if you don’t skip a meal, weight loss is more likely to be a key benefit as long as the meals you are eating are generally balanced with lots of vegetables, nuts and seeds, some fruit, fish, free-range, organic poultry, and grass-fed meat. There are lots of variations in eating windows. You can start with 12 hours and then move onto 10 hours which is quite manageable for most. The longer you fast, the greater the health benefits. Whatever your eating window, always ensure you do not eat within 2 hours of going to bed so that your food is digested efficiently and digestion doesn’t interrupt your sleep.
So the positive effects of sticking to an eating window, and fasting outside of that time, is not just weight loss but this is clearly an important one for many. Other benefits include a decrease in systolic blood pressure, an increase in insulin sensitivity, reduced risk of cardiovascular disease and protection against memory loss. When we fast our bodies burn fat instead of sugar so fasting enables us to hack into our fat stores and burn it as energy instead of sugar. IF also increases our levels of growth hormone which usually decreases with age and improves our circadian rhythm.
IF increases our cells’ resiliency, the stress it creates on our cells causes them to bounce back bigger and stronger. In some cases of fasting, a process known as autophagy is activated. Autophagy means ‘self-eating’. This process kick starts cells to start eating any damaged or dysfunctional cells and debris that are floating around. If these hang around too long they can affect our health or even lead to cancer growth. That’s why cancer patients are often told to fast. Our cells basically clear out the waste we produce from metabolism. As to when autophagy kicks in, this is dependent on what you are eating when you are not fasting and your metabolic flexibility (how efficient your body is at burning all types of fuel) but autophagy is definitely something to aim for to maintain a healthy body as we grow older.
A recent study in patients with Metabolic Syndrome on medication ate during a 10-hour eating window for 12 weeks and lost weight, reduced waist circumference, body fat percentage, visceral fat and, blood pressure. Metabolic Syndrome affects an estimated 1 in 3 adults age 50 or over in the UK and increases the risk for diabetes type 2, heart disease and stroke. Scientists are finding that erratic eating patterns disrupt circadian rhythms and metabolism. Eating and drinking everything (except water) within a consistent 10-hour window allows the body to rest and restore for 14 hours. Your body can then anticipate when you will eat so it can prepare to optimize metabolism.
Fasting isn’t for everyone and is not recommended for those with a hormone imbalance, a woman trying to maximize fertility, if you suffer from an eating disorder or if you are experiencing a lot of stress.