Saturday, May 11, 2019

Life with Chronic Conditions: Intermittent fasting



Recently my brother told me he was “intermittent fasting” as a way to control his pre diabetes. So far, it was working very well for him and he had no problem adhering to the schedule.

In college, I found that if I ate only one large meal in the middle of the day, I not only kept weight off but I felt good. With the passing years, pregnancy and nursing, I definitely got out of that habit, but more recently gastric reflux has me finishing dinner by 7pm or earlier. So the combination of my brother’s and my experiences, made me take a closer look at the various articles I was coming across on IF (intermittent fasting).

A lot of the research has been done on animal models and looks very promising, but does it hold true for humans? Is it different for men and women? What about people with chronic conditions?

 For centuries cultures and religions have included fasting, such as Ramadan for Muslims, Lent for Catholics and Yom Kippur for Jews. Buddhist and Hindus also have fast days scheduled throughout the year.  In hunter/gatherer cultures, it would be feast of famine. The change, with year round food availability, as well as “snack” foods, appears to play a part in the high levels of diabetes among Native Americans.

Broadly speaking IF falls into two categories:
a) Alternate Day Fasting: Switching between days you eat more (feast) and others less (fast). There are lots of variations on this with the most popular appearing to be 5:2, where you fast for two non-consecutive days every week.
b) Restricted Eating Window: Instead of restricting what you eat, you restrict the hours you eat. Most popular is the 16/8 method. You fast for 16 hours and eat for 8.

Research is slow in catching up with the hype, but there are indications that IF does help with weight loss, anti aging, diabetes risk reduction cholesterol etc. In fact, the science of fasting has been focused more on disease prevention and longevity then weight loss.

A German study found that while IF does cause weight loss, it doesn’t appear to have an advantage over conventional weight loss diets. American Journal of Clinical Nutrition  Another study of 88 obese women found that they lost more weight and improved their health by using IF while following a strictly controlled diet. However, this was only a 10-week study. Obesity 

There is some research that indicates that IF may help reverse type 2 diabetes, while some animal studies say it might increase the risk.

Interestingly, the study that has shown promise in reversing memory loss associated with Alzheimer’s disease, implemented a 36-point program targeting life styles. One of these was fasting 12 hours between dinner and breakfast. Reversal of Cognitive Decline. 

Researchers at Johns Hopkins School of Medicine have found that intermittent fasting—limiting caloric intake at least two days a week—can help improve neural connections in the hippocampus while protecting neurons against the accumulation of amyloid plaques, a protein prevalent in people with Alzheimer’s disease. “Fasting is a challenge to your brain, and we think that your brain reacts by activating adaptive stress responses that help it cope with disease,” says Mattson. “From an evolutionary perspective, it makes sense your brain should be functioning well when you haven’t been able to obtain food for a while.” Johns Hopkins Health Review

The limited research on humans does seem to show that results vary between men and women. Some women have experienced missed periods, metabolic disturbances and even early onset menopause. However, other women swear by it. So many variables could be at play here, including age, whether you’ve had children, been through menopause etc.

There are also questions about when is the best time to fast. Some research indicates eating earlier in the day is better than later. However, given the common social practice of going out for dinner, this could be problematic for many.

In short, a lot more research is needed.

All of this noted, anyone who has diabetes; eating disorders that involve unhealthy self-restriction (anorexia or bulimia nervosa); use of medications that require food intake; adolescents; and pregnant or breast feeding women should not consider IF. Further, anyone with a chronic condition needs to check with their medical provider before trying a significant diet change and should be monitored for its effectiveness or possible side effects.

Further Reading


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