The Facts on Intermittent Fasting
By Lisa Larkin, MD, FACP, NCMP, IF
Every few years a new fad diet makes its rounds in the news and social media feeds. The latest buzzworthy approach to weight loss is intermittent fasting.
Intermittent fasting (IF) is just what the name suggests: It is a cycled pattern of eating and not eating (fasting). There are five methods of intermittent fasting:
- 16:8 – Fast for 16 hours, eat over an 8-hour window
- 18:6 – Fast for 18 hours, eat over a 6-hour window
- 5:2 – Eat your normal diet 5 days a week and limit calories to 500 on 2 days of the week (low calorie days should be between normal days)
- Warrior Diet or One Meal a Day (OMAD): Fast for 20 hours and eat one large (healthy) meal
- Eat-Stop-Eat: Fast for 24 hours once or twice a week
It goes without saying that you should talk to your doctor before trying intermittent fasting or any other fad diet.
How intermittent fasting works
Our bodies are designed to go several hours without eating. When we do eat, food is broken down into molecules that enter our bloodstream. Vitamins and minerals are transported to cells, helping our bodies and systems run smoothly.
Carbohydrates and refined grains are broken down into sugar and used for energy. Insulin, a hormone made by the pancreas, breaks down carbohydrates and helps store excess energy. When we eat too much, stores become full and sugar is broken down into fat –ultimately adding to your waistline.
Intermittent fasting can help you lose weight by slowing the production of insulin. When the body doesn’t have insulin to convert energy into fat, human growth hormones burn fat for energy.
What to eat during fasting, eating periods
Along with a clear timetable of when you can eat, there are also certain foods and drinks you should be focusing on – and avoiding.
During your fast, you can have:
- Black coffee
- Green tea
Avoid artificial sweeteners in diet drinks as they can break your fast and trigger a higher production of insulin.
When your fast is over, it’s important to take a restrained approach to eating – even though you’re hungry. Keep these tips in mind for a successful fast:
- Avoid refined sugars and starchy carbohydrates
- Moderate your protein intake
- Eat more natural fats, like avocados, eggs, nuts and chia seeds
- Eat whole foods (unprocessed foods)
- Stay hydrated
Benefits of intermittent fasting
Research has shown that IF can be a safe and effective way to lose weight. Scientists have also linked IF with a reduced risk in cancer and improved efficacy of anti-cancer medicine.
Other benefits of IF include:
- Reduced inflammation
- Reduced risk of heart disease
- Natural cleansing of cells, which can help slow the aging process
- A stronger immune system
The right approach to intermittent fasting
Intermittent fasting takes a deliberate approach to planned meal times. Whichever method you take, it’s important to keep a few things in mind:
- Eat healthy meals and snacks during eating periods. Just because the fast is over doesn’t mean you can – or should – eat whatever you want. A plant-based diet that’s high in fresh fruits and vegetables, whole grains, dairy and lean protein is the basis of all healthy eating. Avoid foods high in sugar as these can cause a spike in insulin and load your body’s stores with fat cells once again.
- Lasting weight loss comes from lifestyle changes. Even though IF can be very successful for some individuals, healthy eating and regular physical activity is a key part of losing weight and keeping it off. Healthy choices, including limiting alcohol intake and quitting tobacco products are also in important part of a healthy lifestyle.
- Talk to your doctor. Your doctor can discuss the benefits and challenges of intermittent fasting and help decide if it’s right for you. Your doctor may also be able to connect you with a dietician to build a fasting plan that works for your life and schedule. Discuss how you can make other lifestyle changes to help improve your health – today and in the long run.