Intermittent fasting is a term that describes an eating pattern that cycles between periods of fasting and eating. Much like clean eating, intermittent fasting is not a ‘diet’ per se, but rather an ‘eating pattern’ and lifestyle choice. There are several different methods, but they all involve splitting the day, or week, into eating periods and fasting periods. During a typical fasting periods, you eat very little or nothing at all.
Studies indicate intermittent fasting can be beneficial to your health, particularly as it relates to insulin sensitivity. In short, the eating pattern promotes human growth hormone levels to go up and insulin levels go down, in essence resetting your body to burn fat as a source of energy. When your body adapts to burning fat instead of sugar as your primary energy source, the risk of chronic disease is dramatically reduced. Your body cells promote changes in gene expression and initiate important cellular repair processes. Plus, intermittent fasting inhibits the mTOR pathway, which plays an important role in driving the aging process.
If alternate-day fasting, you eat normally every other day. On days in between, you eat just 25% of your daily calorie needs, in one meal. So if you consume 1,800 calories on Monday, Wednesday, and Friday, you’d eat a 450-calorie meal (and nothing else) on Tuesday, Thursday, and Saturday.
In the 5:2 approach, you eat normally for five days in a row; then for two days in a row, you eat just 400 to 500 calories per day.
In the 16:8 approach, each day is the same: you fast 16 hours in a row, and then eat normally within an eight-hour period, like between 9 a.m. and 5 p.m. For example, in the Good Food Guide’s kitchen we all break fast together, usually around 11:30 with a cup of warm broth followed by avocado toast on a CauliRound, sometimes topped with a french omelet or some smoked salmon. We then have lunch around 4PM and a light salad in the evening. We rarely eat after 7PM.
By simply altering what and when you eat, you can dramatically alter how your body operates. It means the body spends less time and resources on the high energy tasks of digestion and can focus on activities like ridding the body of toxins and repairing and rebuilding tissues. In addition, it puts the body in an ideal state to manage weight, without the need to count calories or measure grams.