Back to fasting!
A closer look at the excellent work undertaken by Dr. Krista Varady.
Back on the 16th I wrote a post that was a follow-up to the previous day’s post about living a long life. My follow-up was called, hardly surprisingly, Postscript to Long Life post.
In that follow-up post, I wrote this,
Over on the Healthy Fellow blogsite, there’s an interview with Dr. Varady. The web link of that interview is here and crossing over and reading the full interview is much recommended. Here’s a taste, pardon the pun, of that interview:
JP: Can you help explain the distinctions between alternate day fasting and caloric restriction?
Dr. Varady: Caloric restriction is basically daily calorie restriction where an individual would restrict themselves by about 15% to 40% of their energy needs daily. So basically every single day you’re undergoing the same amount of restriction, whereas alternate day fasting involves a fast day wherein the individual would only eat 25% of their energy needs. So about 500 calories or so and that’s alternated with something called a “feed day” where the individual would eat ad libitum – so as much as they want. However in our studies we show that people end up losing weight because they can’t fully make up for the lack of food on the fast day on the feed day.
I’ve been in touch with JP wondering if I might have permission to republish the full interview. Unfortunately that wasn’t possible. However JP did say that republishing a couple of paragraphs would be fine and I’m going to be cheeky in adding a couple to the one I already published above!
Anyway, before inserting those paragraphs, let me set the scene. A very quick web search comes across the fact that Dr. Varady is an Assistant Professor at the UIC College of Applied Health Sciences. Her research work is described thus,
My research investigates the ability of novel dietary restriction strategies to facilitate weight loss and decrease cardiovascular risk in obese subjects. The most common dietary restriction protocol implemented is daily calorie restriction (CR), which involves reducing energy intake by 15 to 40% of needs daily. Another dietary restriction regimen employed, although far less commonly, is alternate day fasting (ADF). ADF regimens include a “feed day” where food is consumed ad-libitum over 24-h, alternated with a “fast day”, where food intake is partially or completely reduced for 24-h. ADF regimens were created to increase adherence to dietary restriction protocols since these regimens only require energy restriction every other day, rather than every day, as with CR. Recent findings from our lab demonstrate that ADF is an effective means of facilitating weight loss and improving several indicators of cardiovascular disease risk in overweight and obese subjects. Our findings also show that changes in adipose tissue physiology during weight loss may mediate these improvements in vascular health.
Current research activities
Developing novel diet and exercise regimens to facilitate weight loss and decrease cardiovascular disease risk in humans; Examining the intermediate role of adipose tissue in mediating the cardio-protective effects of diet and exercise; Investigating the behavioral factors that influence adherence to dietary restriction strategies.
So this is one lady that ought to understand the effects of what we shovel down our mouths. OK, on to that interview. From Part One, I selected this exchange,
JP: How long does it generally take for people to adapt to this new way of eating?
Dr. Varady: A lot of the subjects were saying that for the first two weeks it was pretty tough to basically change from a 3 meal a day eating pattern to just eating 1 meal a day and then 3 slightly bigger meals the next day. But they said that about after two weeks they totally got used to it and weren’t that hungry on the fast day anymore. They could undergo these really long periods of fasting without really feeling deprived. The other interesting thing that they were telling us was with regard to the feed day. The people didn’t binge. They only ate about 100% to 110% of their calorie needs.
Then from the second part of the interview, JP underlines an important point, “The truth of the matter is that research into ADF is still in its infancy and Dr. Varady is the first person to admit it. ” I then went on to select this exchange between JP and Dr. Varady,
JP: It seems as though ADF provides a very broad array of health benefits. Do you have a theory about why this is possible?
Dr. Varady: In the human data the main thing you see is weight loss. Even if it’s done in normal weight people. The minute you start losing weight you all of a sudden see an improvement in the majority of these factors. A lot of the effects of alternate day fasting are mediated through weight loss. Losing weight is so tightly correlated with your blood pressure, your cholesterol levels and heart rate, etc.
Fasting May Reduce Age-Related Disease Risk Factors
Source: J Appl Physiol 103: 547-551, 2007 (link)
So this is not something of trivial interest, it’s serious research that could have a remarkable effect on the huge problems of obesity and poor diet that affect millions. Do yourself a favour and read the interview now. Part One and Part Two.
Finally, in that post on the 16th, I owned up to having got my weight down to 161.6 lbs (73.30 kgs). Now here we are having completed my third week of 5:2 fasting and last Saturday morning my weight was 159.0 lbs (72.12 kgs). The routine is very comfortable and as Dr. Varady mentioned, there is no sense of wanting to binge after the two days of fasting.