Diets come and go, but one that has really survived the test of time is intermittent fasting. Intermittent fasting, or IF as it’s known, simply means purposely skipping meals. This is usually done for weight loss purposes, or to provide the digestive system with a break from constantly processing foods.
Weight watchers and life extensionists are both big fans of intermittent fasting but, the question is, does it really work?
TYPES OF FASTING
There are several interpretations of fasting. A simple fast involves eating no food for a set period of time e.g. seven days. However, such a sustained fast is tough, and will undoubtedly lead to hunger, fatigue, and a temporary loss of physical and mental performance.
Intermittent fasting, on the other hand, involves much shorter periods of food abstinence – sometimes just a matter of hours. IF methods include:
Only eat during the early and late evening. No food during the day
Meals are only eaten after 16 hours of abstinence
Eat normally for five days per week, eat no food for two non-consecutive days per week
Standing for every other day, eat one day, fast the next
Fast all day, eat a single large meal at night. Believed to emulate the eating plan of a hunter/gatherer who spent daylight hours hunting, and then ate the food hunted and gathered before retiring to his cave at night
With all fasts, water intake should not be restricted as dehydration can be very unhealthy. Some so-called fasts actually allow you to eat small amounts of fruit while others do not. It all depends on how strict you want your fast to be.
EAT LESS TO LIVE LONGER?
Life extensionists believe that periodic breaks from eating can help you live longer. It’s suggested that fasting reduces metabolic stress, helps the body eliminate toxins more effectively, lowers blood glucose levels, increases insulin sensitivity, and lowers many of the markers of inflammation.
Some believe that periods of fasting also “beef up” the immune system, preparing the body for anticipated periods of hardship. This, they believe, will reduce the incidence of many diseases, leading to a longer life.
It’s no coincidence that populations who purposely restrict food intake, often for religious or spiritual reasons, also live the longest. However, scientific evidence linking fasting to longevity is thin at best.
Eating less can undoubtedly have a big impact on health, and therefore longevity, if only because doing so means you are less likely to be overweight. That in itself can have a huge impact on lifespan and quality of life.
FASTING FOR WEIGHT LOSSContrary to what a lot of pro-fasters might think, fasting is not magical. Missing a meal or two will not supercharge your ability to burn fat. Intermittent fasting works, like every other diet, by simply reducing the amount of food you eat.
Providing you don’t overeat on breaking your fast, any type of intermittent fasting should create a calorific deficit, leading to weight loss. After a fast, your muscle and liver glycogen levels, as well as your blood glucose, will be low, and that means at least some of the food you eat will be preferentially diverted to your liver and muscle cells. This may further enhance fat loss, although that effect is very small.
THE PROS OF INTERMITTENT FASTING
Intermittent fasting is simple – just skip a meal or three! Pick your IF method and then use it consistently, being careful not to overeat when you break your fast. If you binge after a fast, and end up consuming more calories than you saved, it will not work.
This simply means that almost anyone can use IF to lose weight and get lean. It’s a very flexible approach to weight loss, and you can easily modify it to suit your lifestyle. You choose which meals to skip, according to your needs and daily routine.
For example, some people might prefer to eat breakfast and lunch only, and then fast for the rest of the day. Others might be more comfortable skipping breakfast and lunch, and breaking their fast in the early evening.
THE CONS OF INTERMITTENT FASTING
Intermittent fasting may leave you feeling tired, weak, nauseous, and hungry. If you have a mostly sedentary job, you should be able to work through these side effects, but if you have a physically demanding job, or exercise intensely, this may be enough to put you off fasting.
Some people do have a tendency to become overly focused on their first post-fast meal, and end up turning it into a feast. This can undo much of the benefit of fasting. This eat/fast/eat cycle may also exacerbate any existing predilections to disordered eating. This is not a diet plan for people with a history of any type of eating disorder.
SO, DOES INTERMITTENT FASTING WORK?
Yes! But mainly because it restricts the amount of food you eat. All diets do this, but IF does it in a very simple and easy to implement way. It may help you live longer, but mainly because it prevents weight gain, or aids weight loss. Being overweight is inextricably linked to poor health and premature death.
Is it for you? Maybe! The only real way to see if intermittent fasting is right for you is to give it a try. If you feel good, stick with it. If you feel less than stellar, look for a different way to control your food intake.