Intermittent fasting has been in the zeitgeist lately it seems, and for good reason; people the world over are reporting increases in energy, weight-loss, mental clarity and more. But is it safe? And how long can you fast for? This case study provides some very interesting insights. Of course, the obvious limitation of a case study is that N equals 1. However, I still think that case studies can be very useful in certain situations. This is one of these situations, as the methodology in this study was rather extreme. If you’d rather see the video breakdown of this, click here.
The study was on a man of 27 years, who weighed 456 pounds before beginning. The methods were very simple: he would fast. In fact, he fasted for 382 days straight. He was allowed to consume “non caloric fluids ad-libidum.” (1). He was given a multivitamin for all 382 days, yeast and vitamin C for the initial 3 months, and paladac (a multivitamin used to treat vitamin deficiencies) for the final three months. He was also given potassium supplements between day 93 and day 162, and sodium supplements from day 345 to day 355. He was an inpatient for a period of time, but then allowed to live on his own.
So, what happened? Well, he didn’t die. In fact, “…fasting in this
patient had no ill-effects.” (1). He also lost 276 pounds, going from 456 pounds to 180 pounds. After 5 years, his weight was stable at 196 pounds.
Here’s where this gets pretty damn interesting. His blood glucose decreased “systematically” and stayed at about 30mg/100ml. As a reference, a diabetic with hypoglycemia may have a blood sugar of less than 70mg/100ml. However, the patient ” remained symptom-free, felt well and walked about normally” (1). Basically, he should have been extremely tired, shaky and irritable due to low blood sugar. So why wasn’t he? Ketosis. When carbohydrates are restricted to usually 5-10% of calories, the body will enter ketosis and begin to use its stored fat for energy. The same thing happens when you eat nothing. Of course fasts of this length should be very carefully considered, and they would only be applicable in subjects who have considerable amounts of weight to lose. However, this case study provides some very interesting insight into common claims regarding starvation and the way the human body works. Food for thought.