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What is fasting?

Fasting is not consuming any calories or severely limiting calories for a specific amount of time. 

Intermittent fasting is eating on most days but fasting periodically. For example, eating three meals a day for a week then going two days without eating before eating again for a week would be considered intermittent fasting. 

Several fad diets encourage fasting for weight loss. They allow some food, but limit calories to fewer than 800 per day, claiming that you’ll lose weight fast. The cabbage soup diet is one example of a fasting diet. It involves eating only cabbage soup and drinking water for a certain amount of time. Diet plans like this one come with many unproven claims, like getting rid of a pound a day for a month or removing toxins from your body. 

While fasting is likely to help you lose weight, if it’s done without a medical doctor’s supervision, it’s a risky practice that can actually lead to more weight gain in the long run and can cause significant health problems. 

If you are interested in learning about how to effectively diet to lose weight quickly and safely, talk to the doctor’s at Beaumont’s medical weight loss program.

Is fasting safe or effective for weight loss?

Most types of fasting are not safe, nor are they effective for long-term weight loss. Young people who are in good health may be able to safely do intermittent water fasting, but even they should talk to their doctor about whether they can do it safely and, if so, how they should do it. 

Limiting calories too much can lead to weight gain in the future because it can both increase your appetite and slow your metabolic rate. While healthy weight loss programs involve limiting calories (especially limiting calories from processed foods), they do not typically include fasting. If the body doesn’t get the number of calories it needs to function normally, it will go into what some refer to as starvation mode, slowing down and storing calories. This slows the metabolism and makes it difficult to lose weight in the future. The key to successful weight loss and health is to get enough of the right kind of calories. Nutritionists and dietitians can recommend a healthy diet and tell you how many calories you should eat based on your current weight, height, and age and your weight loss goals.

Risks of prolonged fasting

Fasting comes with several risks. For example, fasting (or just not getting enough calories and fluids) can cause:

  • Electrolyte abnormalities
  • Heart arrhythmias 
  • Feeling dizzy or fainting
  • Dehydration
  • Stones in the gall bladder
  • Muscle loss
  • Decreased metabolic rate
  • Constipation
  • Cold intolerance
  • Quick drops and spikes in blood sugar

There are people who should never fast, including:

  • Pregnant women
  • Breastfeeding women
  • People with diabetes
  • Children
  • Elderly people
  • People who have a chronic disease or health condition

How to lose weight safely

The best way to lose weight is to change your lifestyle and eating habits to incorporate healthy eating and exercise. This is much more effective in the long run than using fad diets or even dieting in any form. Talk to your doctor or meet with a nutritionist or a dietitian before starting any diet plan to make sure it’s healthy for you and to make sure you aren’t limiting your calories or nutrition too much. You should also talk to your doctor about what types of exercise are safe for you and how much exercise you need to achieve your optimal health and your weight loss goals. 

Following are some tips doctors, dietitians, and nutritionists might give you about how to lose weight safely:

  • Exercise most days of the week. Combining a healthy, balanced diet with exercise will help you achieve your health and weight loss goals. Choose exercises you like. You’ll be more likely to stick to them. And remember you don’t have to exercise all at once. If it’s easier for you to go for four 10-minute walks than to walk for 40 minutes straight, do that. Just make sure you get your heart rate up. Many people find it helpful to wear a step counting device like a Fitbit to ensure they get enough exercise. Aim for 10,000 steps per day at first.
  • Drink plenty of water. If it’s difficult for you to drink a lot of plain water, try adding lemon, other fruit, or cucumber slices into your water. 
  • Stay away from soda and drinks flavored with sugar. Limit fruit juice as well, even if it doesn’t have added sugar. You’re much better off eating the fruit so you get the nutrient benefits and the fiber. 
  • Skip diet soda (and other drinks flavored with artificial sweeteners). There’s a new, long-term study out that showed women who drank two or more diet sodas per day had a significantly increased risk of stroke and heart disease. 
  • Eat lots of fresh vegetables. A good rule is to go for darker vegetables and to eat a variety of colors. Leafy greens are a great option. Light lettuce like iceberg lettuce won’t hurt you, but it won’t give you much of what you need either. And because it has so little flavor, people tend to load it up with dressing, turning a health food into a junk food. Fresh vegetables are an excellent way to ensure you get lots of nutrition without lots of calories or unhealthy fats. Avocados, for example, are a great source of healthy fat, and they’re also full of folic acid. 
  • Choose lean proteins. Protein is an important part of every diet, but some types of protein are better than others. If you eat meat, choose white meat poultry (like chicken or turkey), fish, nuts, legumes (beans, peas, peanuts, alfalfa), and low-fat dairy (milk, cottage cheese). Eggs are also a good source of protein, but they do contain fat and cholesterol, so talk to your doctor or nutritionist about how many eggs you should eat every week.
  • Avoid processed meats. Processed meats are full of sodium and other preservatives. There are some lunchmeats that don’t contain nitrites and nitrates, but most still have a high sodium content. Ham, corned beef, and sausages aren’t the best options for health and weight loss either. 
  • Buy most of your food from the fresh aisles. If you fill your cart with fresh foods, you’re well on your way to eating as you should for optimal health. 
  • Stick with whole grains. When you choose bread, pasta, or crackers, choose options that have whole grain as the first ingredient. Oats are also a great option for whole grains. Try to stay away from white bread or anything with bleached flour. You want to make sure you eat complex carbohydrates whenever possible.
  • Don’t worry too much if you slip up. Having a healthy lifestyle and eating well doesn’t mean you can never have sweet or salty treats—just don’t have them every day. If you restrict your diet too much, you’ll be less likely to stick with the lifestyle change than if you allow yourself to splurge every once in a while.

If you’re insistent on intermittent fasting, make sure you talk to your doctor and do it with medical advice. Call 800-633-7377 to request an appointment with a Beaumont medical weight loss specialist.