You may have heard that in order to lose weight you have to eat small meals throughout the day to “fuel” your metabolism. Most dietitians also recommend never skipping meals, especially breakfast, as the ideal way to eat. But, recently, this advice has been flipped on its head with the emergence of very interesting research on the potential health benefits of fasting.
Frances Ashcroft, a geneticist at Oxford University, has suggested that in order to reduce the increasing rates of diabetes and help people maintain their weight everyone should consider fasting at least one day a week. She suggests that this will automatically reduce overall calorie consumption without having to measure portions or count calories. It is also easy and cheap! But is there truth behind this claim? Is fasting beneficial and safe?
There is a significant amount of research in the area of calorie restriction and intermittent fasting (IF). Experts believe that fasting intermittently may actually be what our bodies are used to, in terms of evolution. In the caveman days it was rare to have food around all the time like we do now, so we were forced to fast occasionally. When there is food available, our bodies build muscle and fat so we can survive during lean times. Periods of fasting may also allow our bodies to clear out waste and debris. Some scientists believe that if we are constantly eating, the body is unable to truly “cleanse” itself which may be linked to an increase in chronic diseases.
Much of the research on intermittent fasting has been conducted on people of the Muslim faith during Ramadan, a holy period of fasting. A 2011 study looked at fasting’s effect on inflammation markers, a common cause of chronic diseases. Researchers found that after the fasting period inflammation markers, blood pressure, and body fat decreased significantly all of which could have an effect on long-term health. It has also been found that intermittent fasting may improve insulin sensitivity and may decrease cardiovascular disease markers.
One criticism of intermittent fasting is that our bodies are built to combat the effects of fasts by storing fat during non-fasting periods. So although you may lose weight and have lower inflammation levels during the fast, once you return to normal eating, your body will try to replace what was lost by releasing hormones that cause you to eat more. Fasting may also lead to a slower metabolism because your body will try to conserve energy. A slower metabolism may lead to weight gain once you resume eating normally again.
Is fasting right for you?
For the general population one day of fasting per week or skipping an occasional is probably safe and may be beneficial. If you are diabetic – especially if you are on insulin- fasting is not safe because your blood sugar can drop too low. Pregnant or lactating women should also avoid fasting. For those of us who are generally healthy, fasting may be a good solution to overall lower our caloric intake without much thought. It may also improve insulin sensitivity, reduce our risk of cardiovascular disease and possibly help reduce our weight, although more long-term research is needed on these potential health benefits.
If you are considering trying intermittent fasting, make sure you drink plenty of fluids during fasting periods to prevent dehydration. While you are not fasting, make sure your meals are balanced to help replace any lost nutrients. You also may want to consider taking a multivitamin to ensure you are still getting proper nutrition.
Overall, the preliminary research on the potential health benefits of intermittent fasting is quite interesting. More long-term research is needed to determine if the benefits seen in the short-term studies translate to long-term reduction in chronic diseases.