Fasting can help people lose weight and slow the diseases being overweight causes (Obesity, Feb 2018;26(2):254-268). For several years I have been recommending the various types of intermittent fasting, but perhaps the easiest way to use fasting for weight loss and weight control is just to eat during the daytime and avoid eating at night. A new study from the University of Illinois had 23 morbidly obese adults, average age 45, eat anything they wanted for eight hours between 10 AM and 6 PM, but they were allowed to drink only water and eat no food during the remaining 16 hours (Nutrition and Healthy Aging, June 2018, 4(4):345). After 12 weeks, they had lost an average of three percent of their weight and had a 7mm drop in systolic blood pressure. Compared to people on other types of intermittent fasting diets, they had the same measures of insulin resistance and cholesterol.
After fasting for more than eight hours, you start to lose body fat because your body is forced to change temporarily from its main energy source of the sugar, glucose, to the fat in your body that is converted to fatty acids that pass into your bloodstream and are converted to energy to produce ketones that are also used for energy.
Benefits of Not Eating at Night
The most fattening time to eat is in the evening or just before you go to bed because you don't contract your muscles very much when you sit on the couch or lie down. After you eat, your blood sugar rises and there are only two places that store sugar: your muscles and your liver. Resting muscles remove almost no sugar from your bloodstream and what little they can remove requires insulin to do so. On the other hand, contracting muscles remove tremendous amounts of sugar from your bloodstream and don't even need insulin. When you eat and do not move much afterwards, blood sugar levels rise very high. To keep blood sugar levels from rising too high, your pancreas releases insulin which drives sugar into muscles and liver, and then converts what extra sugar remains to a type of fat called triglycerides. The extra triglycerides are stored as fat in your liver, other organs and fat cells.
Types of Intermittent Fasting
Research has not proven any one method for intermittent fasting to be superior to the other methods. Types of intermittent fasting include:
• Full-day fasting on alternate days
• Fasting a few days a week, such as 5:2, with two days of fasting and five normal days
• Fasting a few days each month
• Fasting during specific hours every day
It is not easy to restrict food when your refrigerator is full and you are hungry. Since fasting for long periods can be painful and hard to do, the most effective way to fast intermittently may well be to fast just in the evening and overnight hours.
Why Intermittent Fasting Works
Why We Use Intermittent Fasting
Intermittent Fasting May Not Be for Everyone
Certain conditions can be worsened by fasting. You should check with your doctor if you are diabetic, have low blood pressure, take medications, are underweight, have eating disorders, or are pregnant, trying to become pregnant or breast-feeding an infant.
• Do not keep foods you want to avoid in your house where they will tempt you during the hours you plan to "fast" (sugared drinks, sugar-added foods, fried foods, foods made from flour, red meat, processed meats and so forth)
• Stock lots of fruits, vegetables, whole grains, beans, nuts and other seeds
• Eat a healthful breakfast such as oatmeal with raisins
• Eat your main meal between noon and 6 PM, with plenty of the healthful foods listed above
• After 6 PM, you can drink water, but avoid foods and all drinks with calories