Intermittent Fasting – What’s the Evidence?

I have always thought that intermittent fasting fits in the ‘fad diet’ group. However, this week, I found a quote from Dr Rhonda Patrick striking – she said everyone should be following some kind of intermittent fasting. That is a bold statement from a scientist; most research uses maybes and mights; phrases such as ‘limitations to conclusions’ and ‘warranting further research’.

So, I delved into the research. And was staggered. There’s a lot of it, and there’s a lot of evidence behind it. Intermittent fasting comprises, essentially, of not eating for a period of time. Examples of this are time restricted eating (e.g. only eating for 12 or 8 hours of the day), or the 5:2 diet.

What are some of the benefits of intermittent fasting? Yes, weight loss, although this is likely just through intermittent fasting creating a calorie deficit (as any other diet would). There’s host of benefits aside from that. For instance, studies show that intermittent fasting causes levels of blood insulin to drop, higher levels of human growth hormone, cellular repair, and in some cases cellular atrophy (death) and renewal. Organs under the stress of fasting have been shown to actually shrink in size, stimulating new cell growth. Furthermore, your metabolic rate can increase, and the decreased insulin resistance can help protect against type 2 diabetes.

Intermittent fasting has been found to help fight inflammation and damage to DNA; both of which contribute to lots of common diseases and aging. It can also reduce blood pressure and improve your good cholesterol to bad cholesterol ratio (in animal studies). Intermittent fasting can protect against cancer (again, evidence from animal studies). The cellular regeneration can potentially help your brain as well, by warding off illnesses such as Alzheimer’s disease.

Some of the most drastic evidence is in lifespan. Nematode worms are a common model organism used in research – their lifespan doubled in intermittent fasting studies! Others in rats show an 83% increase in lifespan.

There is one note of caution; most of the studies so far in humans have been in animals, or in humans – mainly men. There has been a least one study that suggests that women following a similar fasting pattern to men may actually worsen blood sugar level control, and tests in rats showed that alternate day fasting (for months) affected their reproductive cycles. As discussed in my previous article, women’s bodies are very sensitive to energy intake due to their reproductive cycle, so they should approach intermittent fasting differently to men. For example by taking shorter fasting periods (starting with 12 hours, which can build up to 16 hours) and spacing the fasting periods out amongst the week.

First, ask yourself, why do you want to do it? If the answer is weight loss, a different approach may be better for you.

Has anyone tried intermittent fasting and if so, what are your experiences?

© 2018 by The Plan Harrogate. Proudly created with

The Plan

1 Westmoreland Street