Intermittent Fasting Lifestyle for optimal health and wellness?
Intermittent Fasting Lifestyle
Since we are approaching a time of the year that can be health and nutritionally challenging, I thought it would be an opportune time to talk about Intermittent Fasting (IF). You may have heard about it before or maybe you already have an intermittent fasting lifestyle.
It has really fallen in vogue over the last years. Many people have chosen this as their way of eating. I find it interesting that this is suddenly all the rage. Fasting is something that has been practiced for ages and by many religions. Perhaps our ancestors inherently knew?
I have pretty much tried every single way of eating out there. Not for weight loss purposes, but as part of a health quest. I wanted to feel my best and get rid of heartburn and muscle aches. I experimented with everything from veganism to Atkins.
Finally, I found the right combination that works for me and it includes an intermittent fasting lifestyle. I have been eating this way for the past 2-3 years. I don’t do it every day, but 4-5 times/week. When I don’t do it, I only drink a green juice or a protein smoothie in the morning, so nothing very heavy or hard to digest.
Intermittent fasting refers to a time period when you significantly restrict your calories. It typically refers to a period of at least 12 hours and definitely may be much longer. For purposes of daily intermittent fasting, most people will fast for 14-16 hours and concentrate the bulk of their calories over the remaining 8-10 hours of the day. You may see this designation 16:8. This refers to fasting 16 hours and eating only the remaining 8.
Some people do this every day and others eat this way a few days a week. Still others do a 24 hour fast two days a week. All of them are ways people practice an intermittent fasting lifestyle.
I personally don’t fast more than 16 hours because I find myself getting too hungry and wanting to binge eat. This is actually one of the problems that can come from IF. It is important that you find the timing and balance that works for you. Also, as most things, the longer you do it, the easier it gets.
So, why would people want to do this? Well, upon review of the literature (medical term for looking up the research available on this topic), over 700 research articles popped up in our medical search engine.
We have a problem of epidemic proportions with obesity in developed countries, particularly in the United States. We know that over-eating is a culprit behind many of the metabolic problems we are seeing today. One such problem is the huge increase we have with insulin resistance and the development of Type II Diabetes Mellitus. Combine this with the lack of physical activity, so common in our current modern lifestyle, and you have the perfect storm for a health crisis.
From an evolutionary standpoint, it seems unlikely that early man ate the three conventional meals that we eat now days. Food was scarce and hard to come by, so you ate when you could find food. Early man developed mechanisms to help him cope with this. We needed to function well in a fasting state. Since we haven’t been around for that long and we have had an even shorter amount of time in our current standard modern living, it is likely and possible that we have not evolved from these mechanisms. This may contribute to the problem we have today.
Intermittent Fasting lifestyle for health
As I mentioned, there is quite a bit of research on this topic. I summarized it so you don’t have too look at all of it. However, if interested, I include links to references. That way, you can read further if you would like to know more about an the research behind an intermittent fasting lifestyle.
One caveat I found, is that there isn’t a lot of research comparing IF with the usual diet modality of caloric restriction. Now, IF is not caloric restriction per se. However, if you have less hours to eat in the day, you naturally tend to consume less calories. Hopefully, future research will start looking at differences between these two.
Also, the human studies tend to be small and short in duration, so really not the best. Much of the information we have is from animal studies.
All right, with this in mind, lets start exploring the possible benefits an intermittent fasting lifestyle can provide.
Longer Life Span
Animal studies, even from way back in the 1990’s, show that when rats are fed in an alternate day fast schedule (3 meals one day alternating with a fasting day the next), rats lived longer than their everyday three meal a day counterparts. How much longer? Well, that depends. If they were started at a very young age, twice longer. If started at middle age, 30-40% longer. So, the earlier you start the better. However, you can still reap benefits even if starting later.
Improved cognitive function
A study on mice showed that mice on intermittent fasting had better learning and memory than their non-fasting counterparts. In addition, another study found that middle age rats that were exposed to IF had improvement in motor coordination and learning response.
If we look at brains that experience injury, we can find numerous studies showing that, when initiated prior to a stroke, alternate day fasting can reduce brain damage and improve functional outcome in animal models of stroke.
In rat models with spinal cord injury and chest injury, alternate day fasting initiated prior to the injury and continued thereafter significantly improved functional outcome and reduced spinal cord lesion size.
Here we have some human data: As we mentioned many religions have fasting practices during particular holidays. In Muslim groups who fast during Ramadan (from dawn till dusk), several studies have shown that many subjects lose weight during this time and exhibit improvements in several health parameters. Unfortunately, fasting times vary quite a bit. This is due to the large variability in the number of fasting hours depending on the time zone. This makes it difficult to see the ideal fasting time.
It is unclear if IF is superior to caloric restriction diets, but mot studies agree that it is at least as successful in achieving weight loss. This is good news because most people can’t tolerated caloric restriction diets for prolonged time periods. A good reason why so many diets fail.
Increased insulin sensitivity
When rats are fed a high fat diet, they develop insulin resistance and diabetes, which can be ameliorated by maintaining them on an 16 hour daily fast (eat only for 8 hours during the day).
In humans, two studies with 2 days/week of IF have reported greater reductions in insulin resistance versus caloric restriction diets. They studied overweight and obese non-diabetic subjects. In the first study, the subjects on the IF diet exhibited a 25% greater reduction in insulin resistance compared to the caloric restricted group when measured in the morning after five normal feeding days. There was a further 25% reduction in insulin resistance compared with caloric restricted group the morning after the two energy restricted days.
Improved lipid profile
Levels of circulating cholesterol and triglycerides are reduced in animals on IF diets.
In human studies, the first trial of IF for weight loss, amongst 10 obese subjects with asthma, tested regular intake days alternating with days that had less than 20% of their normal calorie intake. This study reported beneficial reductions in serum cholesterol and triglycerides, markers of oxidative stress (oxidative stress results in the formation of free radicals which can be harmful to our cells) and inflammation.
Prevention of cardiovascular disease
The effects of intermittent fasting in animal studies are similar to those seen with exercise initiation! Within 1 week of initiation of alternate day fasting in rats, resting heart rate and blood pressure are significantly reduced, continue to decrease through 2 weeks, and remain reduced on both fasting and feeding days.
Another interesting study showed that rats who were on an intermittent fasting schedule prior to undergoing a heart attack showed a smaller affected area in the heart and faster healing of the heart post attack.
There are approximately 13 types of cancer directly associated with being overweight. Clearly, weight control is essential for cancer prevention!
Recently, a series of studies in animal models have shown that periodic fasting lasting 2 or more days can be as effective as chemotherapy in delaying the progression of a wide range of cancers but, more importantly, can protect normal cells from the toxic effects of chemotherapy drugs while sensitizing cancer cells to the treatment.
Also, a severely restricted diet that mimics IF started at middle age was effective in causing a major reduction in tumor incidence, in addition to delaying tumor onset and reducing the number of sites with tumor-like lesions, suggesting a reduction in metastatic cancers.
Positive Impact on the Microbiome
Finally, with all the rage about the gut microbiome (friendly bacteria that live in our intestines) and probiotics, you should now that IF can help there too!
Studies suggest that cyclical fluctuations in our friendly gut bacteria occur depending on our fasting and feeding patterns. Diet induced obesity decreases these fluctuations and time restricted feeding (as is IF) seems to restore these fluctuations. Furthermore, time restricted feeding appears to affect bacteria that influence our metabolism.
A study with IF in rats showed that the gut microbiota improved by increasing the abundance of good bacteria and reducing the not so good.
There is simply so much potential for IF! No wonder so many are choosing an intermittent fasting lifestyle for optimal health. Of course, we will need to see more human studies. Still, the preliminary data is very exciting and, if you haven’t tried it yet, you may want to give a try and see how you feel! I know it has definitely made a difference for me. What do you think about IF?