"Scientific data seems to show that as well as helping to shift pounds, this alternate-day dieting can help us live longer and reduce the risk of diseases such as cancer, diabetes and even Alzheimer’s.
While the idea that you can eat anything on your free days sounds great — especially for dieters who struggle to stick to low-calorie eating plans long-term without falling off the wagon — many nutritionists believe that those on the alternate day diet could end up over-indulging on ‘feast’ days, and actually put on weight. However Dr Krista Varady of the University of Illinois in Chicago, one of the scientists involved in research into intermittent fasting, insists that this doesn’t happen.
‘Our studies 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. And people in our studies didn’t binge. They only ate about 100 per cent to 110 per cent of their calorie needs.’
.... "It remains to be seen whether this is a long-term solution for those with weight problems, or is just another short-lived diet craze that will go the way of the Grapefruit Diet, the Cabbage Soup Diet, and other extreme plans women have subjected themselves to over the years.
But is a diet that nutritionists warn may spark an eating disorder really worth the risk?"
Steven Austad: "There are some people following near-starvation diets in an effort to mimic the dramatic results seen in rodents, but not that many, because most people couldn't face that kind of dietary deprivation. "Don't feel so bad that you can't get yourself to this phenomenally lean, you might say emaciated, body state," says Austad, "because there's not any evidence that that's really going to help you live a lot longer anyway." But he says there's still no doubt that exercising and avoiding being overweight or obese will keep you healthier for your normal life span.
YOUR DAILY DOSE... WHAT ARE THE RISKS?
If you think taking daily aspirin is a harmless way of improving overall health, think again. The risk of serious side effects is very low. But recent Italian research showed that long-term, low-dose aspirin usage was linked to a 55 per cent higher risk of bleeding in the digestive system, and a 54 per cent higher risk of bleeding in the brain.
Krista Varady research into Alternate Day Fasting (ADF) is at the very early stages with low trial numbers. Further research is needed using much larger RCTs. The theory is that ADF mimics our hunter-gatherer evolutionary past when feasting was followed by periods of famine.
JP: Is it fair to say that you believe that the actual practice of prolonged fasting may impart added benefits beyond that of just reducing calories on alternate days? Dr. Varady: That’s another study I want to design to see if we actually see different effects if we compare people on alternate day fasts that are consuming their meals within that amount of time (12:00 – 2:00) compared to people that are allowed to eat throughout the day. I think that if we did do that study, we’d actually see better effects from people doing the confined eating period. I think our bodies are used to that from the hunter-gatherer days where we’d have days of plenty where we could eat a bunch and then all of a sudden there was nothing out there and we’d have to fast. So I think our bodies are capable of doing that.
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. Research http://www.nature.com/oby/journal/vaop/ncurrent/pdf/oby201054a.pdf
The ability of alternate-day fasting (ADF) to modulate adipocyte parameters in a way that is protective against coronary heart disease (CHD) has yet to be tested. Accordingly, we examined the effects of ADF on adipokine profile, body composition, and CHD risk indicators in obese adults. Sixteen obese subjects (12 women/4 men) participated in a 10-week trial with three consecutive dietary intervention phases: (i) 2-week baseline control phase, (ii) 4-week ADF controlled feeding phase, and (iii) 4-week ADF self-selected feeding phase. After 8 weeks of treatment, body weight
and waist circumference were reduced (P < 0.05) by 5.7 ± 0.9 kg, and 4.0 ± 0.9 cm, respectively. Fat mass decreased (P < 0.05) by 5.4 ± 0.8 kg, whereas fat-free mass did not change. Plasma adiponectin was augmented (P < 0.05) by 30% from baseline. Leptin and resistin concentrations were reduced (P < 0.05) by 21 and 23%, respectively, post‑treatment. Low-density lipoprotein cholesterol (LDL-C) and triacylglycerol concentrations were 25% and 32% lower (P < 0.05), respectively, after 8 weeks of ADF. High-density lipoprotein cholesterol (HDL-C), C-reactive protein, and homocysteine concentrations did not change. Decreases in LDL-C were related to increased adiponectin (r = −0.61, P = 0.01) and reduced waist circumference (r = 0.39, P = 0.04). Lower triacylglycerol concentrations were associated with augmented adiponectin (r = −0.39, P = 0.04) and reduced leptin concentrations (r = 0.45, P = 0.03) post-treatment. These findings suggest that adipose tissue parameters may play an important role in mediating the cardioprotective effects of ADF in obese humans.
JP: I’m fascinated with the role that blood sugar control and insulin sensitivity play in various aspects of health. Does ADF have any significant impact on how the body manages blood sugar and insulin levels? Dr. Varady: Beyond the weight loss, fasting might play a role in that. You’re not having food come into your body. Therefore you’re not having insulin released by your pancreas. So really you’re having this time where there shouldn’t be much insulin circulating around in your body, which is a good thing because insulin is lipogenic. So it basically causes your fat to be stored and not broken down. It also interacts with certain growth hormones – IGF (insulin-like growth factor) for one, which is related to growth hormone. And that can actually stimulate cell proliferation. So insulin does play a role potentially in cancer risk.
JP: Many people are interested in learning about natural ways of slowing down the aging process. Is ADF a good candidate in this arena? Dr. Varady: If you have a diet that will slow the rate of cell turnover that’s actually slowing aging technically. I think there’s definitely going to be more data coming out regarding that. I guess after we do most of these weight loss and heart disease efficacy trials, I’d also be interested at looking at the aging process as well
I was not clear from the Michael Mosley Horizon film whether on the fast days you could split the 600 calories into 1 meal or up to 3 meals ie 3 x 200 cals. Mark Butcher has found that the 600 calories should be used in 1 meal. Mark Butcher emailed Longo, Mattson and Vardy from the film.
Advocates fasting (within the context of 24 hours) for as long as possible. He suggests that if you have to consume 5/600 calories then they should be consumed as one meal, very early in the morning so as to maximise the length of the fast.
With regard to IGF-1 reduction it is better to do 4 days of (consecutive) fasting every few months and then skip meals during the week to maintain weight and try to adopt a plant based low protein diet. An alternative to the 4 days fasting is just to fast on 2 days at a time as in the 5-2 plan but you must also try to move to a healthy diet, plant based and low protein.
Krista A. Varady
With regard to how you should eat (if at all), on a fast day: So far, we have performed studies permitting people to eat 600 kcal between 12pm-2pm. We find that this strategy works well for most people (whereas a complete fast for 24 h does not). We have yet to run a study where we allow people to consume the 600 kcal as 6x100kcal (or 3 x 200 kcal) smaller meals throughout the day. However, we are planning to run this study within the next year. Krista Varady says ‘eating the 500 calorie allowance throughout the day would prevent a persons body going into a fasted state’. Since it is the fasted state that is so beneficial to us, this information is critical.
Mark P. Mattson
1. A complete fast (no food) with hydration maintained with non-caloric beverages will be superior to consuming 600 calories on the fasting days.
2. Eating the 600 calories at one meal will be superior to eating several smaller meals spread throughout the day. By eating only one meal, the body goes essentially 24 hours with no food. This results in adaptive cellular stress responses which we believe is particularly good for the brain.
3. In the case of the 5:2 diet, we do not know whether better health benefits are realized with two consecutive days of fasting versus any two days of fasting during the week.
It would be much better if you could just get through a fast day without eating at all. Obviously, very few people are able to do that, so if you are going to eat a (600 for a man, 500 for a woman) calorie reduced meal, you are much better to consume that as one meal than to spread those calories throughout the day. This is because the stress that going for 24 hours without food places on your brain actually has produced identifiable positive brain responses such as the growth of new brain cells. It’s like a workout for the brain. How to add that into an intermittent fasting or alternate day plan?
Easy. Either, take a note of what time you last ate on the feed day prior to your fast and then do not consume your 600 calorie fast day allowance until 24 hours has past. So, if you ate at 6pm on a feed day, do not eat your 600 calories until 6pm on the fast day. That way, you’ve gone 24 hours without food AND you get to eat (albeit a restricted) dinner! If that doesn’t grab you, eat breakfast on a fast day and then don’t eat again until your breakfast the next day.
Science Writer David Stipp RSS Feed highlighted new research on Calorie Restriction in Monkeys published this week in Nature (ref 4).
1) On Calorie Restriction, Monkeys, Magic and Medicine - Compares to Wisconsin 2009 study. David Stipp comment 'CR hasn’t extended lifespan in all species, nor has it worked in certain strains of rodents. In the latest study on the topic, it failed to extend lifespan in a long-term study in rhesus monkeys at the National Institute on Aging (NIA)....the study suggested that CR improved late-life health in the monkeys, but the effect was modest and gender-specific.... dietary factors potentially gave a boost to the NIA controls’ health as they aged, which might have contributed to the fact that they were about as healthy and long-lived as the monkeys on CR in the study '
6) http://www.wired.co.uk/news/archive/2012-08/30/calorie-restriction-diets - Luigi Fontana comments that possibly no effect of CR seen because monkeys were all on high protein diets. In humans, those hormones decrease only when protein intake is dramatically reduced. It's not enough to cut calories alone. "It's possible that we don't see some of the beneficial effects of longevity in these monkeys because they were on a high-protein diet," Fontana said. "The old idea is that a calorie is a calorie. When you restrict it, you have a beneficial effect. Our data and other data suggests this isn't the case. The quality of the diet matters," Fontana continued.
7) http://www.newscientist.com/article/dn22231-eating-less-fails-to-extend-monkey-lives.html Luigi Fontana believes both studies should have paid more attention to dietary composition. "Fifteen per cent of the monkey diet came from protein – that's too much," he says. "Our work suggests lowering protein, rather than calories, may be the key to increasing longevity – so reducing protein intake could have led to better results." De Campo agrees that dietary composition might play a role in lengthening life, but claims the benefits of calorie restriction are still strong. "Although we don't have the same lifespan findings as the Wisconsin group, what's really important is that we did show similar improvements in health."