By Ravi Menon, MD
Department of Internal Medicine
Many of us, especially at this time of year, are looking for a way to lose weight and improve our health. One method you may have heard about is intermittent fasting. Technically, intermittent fasting isn’t a diet, it’s time-restricted eating, where you eat only during certain periods of the day and fast during the rest of them.
Intermittent fasting has become popular because it can offer real health benefits, including weight loss, lower blood sugar and improved lipid profiles.
Keep in mind that intermittent fasting isn’t really new. People have practiced it for thousands of years. For instance, many religions throughout the world have long made a practice of fasting. And although most of us are used to eating three meals a day along with snacks, this hasn’t always been true. Early humans were only able to eat what they could hunt and gather, and could go days without food due to scarcity. Evolution has made us easily able to go without food for surprisingly long periods of time.
Fasting Isn’t Right – or Safe – for Everyone
Always check with your primary care provider before you start fasting. Fasting can be inappropriate or even dangerous for some people, including:
- Children and teens under age 18
- Women who are pregnant or breastfeeding
- Those with a history of eating disorders
- People with Type 1 diabetes who take insulin
- People with Type 2 diabetes who have poor blood sugar control
Your healthcare provider can let you know if fasting is appropriate for your medical condition and explain any precautions you might need to take.
How Do I Get Started?
It’s pretty easy to begin intermittent fasting. All you have to do is allow more time between your meals. It can be as simple as stopping dinner at 7:00pm and not eating anything else until 7:00am the next day. That may be a simple 12-hour fast. Some of the other more popular fasting regimens are listed below:
16:8: This means fasting for 16 hours and eating only in an 8-hour window. So, you would finish dinner at 7:00pm and have your first meal the next day at 11:00am.
OMAD: This is an abbreviation for “one meal a day.” You can choose the time to eat your meal. Remember, no snacking allowed!
5:2: In this type of fast you eat normally for five days during the week and then fast or just eat a small number of calories (around 500) on two days of the week. These two days do not have to be consecutive days.
There are many different variations on the above type of fasts. For instance, some people try a 14-hour fast at first and then move on to longer fasts as fasting becomes more manageable for them.
How Does Intermittent Fasting Work?
When fasting, you are obviously consuming fewer calories; but there is also another key reason fasting works to help you lose weight – it helps lower your blood insulin levels. When your body’s insulin levels are too high it stimulates the creation of new body fat and also works to inhibit the breakdown of stored fat which prevents you from losing those excess pounds.
Keep in mind that when fasting you must stay well-hydrated. Keeping your body well-hydrated will help you stay on track. It’s best to consume drinks that are free from calories and sweeteners such as water, sparkling water, and tea and coffee without any additives (although if you put some cream in your coffee we won’t tell anyone).
One way to make intermittent fast more productive is eating healthy food when you finally break your fast. You will want to eat whole, healthy foods, not processed foods. So please don’t break your fast at a fast-food restaurant! It’s best to cook a healthy meal at home. (You can find some healthy recipes here.) Also, you don’t want to consume more food than normal just because you are breaking your fast. It should be the normal amount of calories you would consume if you weren’t fasting.
Keep in mind that it can take some time for your body to adjust to intermittent fasting. You will probably feel hungry and possibly a little cranky as you adjust to a new eating routine. However, after a few weeks most people adjust and are able to stick with their fasting plan.
About Ravi Menon, MD
Dr. Ravi Menon is a former Lieutenant Colonel in the United States Army where he most recently practiced at Hanscom Air Force Base Health Clinic. “I had the opportunity to treat a broad spectrum of cases as an internist. I took care of soldiers, retirees, soldier’s families, as well as many others in both outpatient clinics and military operational settings; it was a great experience and an honor to serve. Practicing in the military is...
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