Posted on 01/23/2021 11:00:07 AM PST by nickcarraway
Sometimes it seems as if the diet world is nearly as polarized as the political sphere.
Especially when it comes to Intermittent Fasting (IF). I wrote a piece about it last year and, almost immediately, saw people sub-tweeting me to complain about promoting an eating disorder in the name of wellness. That’s a pretty stock response to the mere mention of IF in some circles.
On the other end of the spectrum are the die-hard devotees of this popular weight-loss plan, which places more emphasis on when people eat than what they eat. Earlier this fall, when Dr. Ethan Weiss, a cardiologist and researcher at the University of California, San Francisco, published results from a study that cast doubts on the efficacy of IF, he got an earful.
“I certainly had a mix of responses, either on email or social media,” recalls Weiss. “There were some people who were super cool and really interested, but there were some people who were extremely unhappy. I got a lot of comments from people like, ‘You idiot, how can you tell me that this form of restricted eating doesn’t work when it worked for me?’”
In fact, fasting worked for Weiss, too, who lost weight over the six years he was on the regimen, so he’s likely the last person who would have said that IF can’t work. And, indeed, he never said it didn’t work. What the researcher did say was that he conducted a randomized control study where the research subjects on IF were told to eat whatever they wanted so long as it was only in an eight-hour window, and they failed to lose a significant amount of weight — only two pounds in 12 weeks.
So, does it work? Or not? The study flew in the face of a lot of anecdotal evidence from individuals who had had success, including Weiss, himself. He expected his research to confirm that this was an effective way to lose weight and was rather surprised by the results.
Intermittent Fasting is wildly popular and famously used (in some form or another) by everyone from the GOOP set to Silicon Valley tech bros. Part of its appeal is that it’s simple, since there are no points to count or foods to weigh. And, although most people who follow it reduce their intake of processed carbohydrates, fasting isn’t an elimination diet — you don’t have to give up an entire food group.
In addition, it’s been championed by Toronto’s own Dr. Jason Fung, nephrologist and founder of the Metabolic Clinic, in North York with a self-reported high success rate in reversal of diabetes and weight loss. The idea behind it largely revolves around insulin, which controls our blood glucose levels. When we eat, our insulin levels go up. The theory has it that, if we let our insulin flat-line instead, we’ll burn off our stored energy — a.k.a. fat.
Conversely, Fung argues that, failing to regulate insulin can raise your risk for other health problems, including type 2 diabetes, obesity and breast and colorectal cancer, the latter two of which are explored in his new book, “The Cancer Code: A Revolutionary New Understanding of a Medical Mystery.”
“The World Health Organization has classified 13 different types of cancer as obesity-related,” says Fung. “So the key is that, if you are overweight — and that’s affecting more and more people — it’s important to bring that weight down. And if you have type 2 diabetes, which is becoming a bigger and bigger problem over these last 10 years, reversing it will reduce your risk of those associated cancers.”
All of this sounds simple enough, right? There are a lot of potentially complicating factors, however, starting with the issue that there’s no peer-reviewed research at this point to prove the theory. And, although fasting isn’t new (Fung points out that it’s a component of several traditional practices in well-established religions), we don’t know how sustainable a long-term fasting regimen is, especially when it comes to the more extreme fasts that some advocates have endorsed. It’s one thing to skip breakfast, but entirely another to embark on a 36-hour fast.
In fact, the length of the fast is one thing Fung thinks went wrong with the aforementioned University of California study. The design had been based on a study that showed rats lost weight when restricted to an eight-hour eating window. Rats, however, have a much faster metabolism and the human equivalent to a 16-hour rat fast is more like 24 or 36 hours, he explains. So, letting a rat eat anything it wants over eight hours is not at all the same as telling humans to load up on all the good things in their eating windows.
“So the problem is, if you say, ‘Eat whatever you want,’ and they’re eating pizza and french fries all throughout the eight hours and then not eating for the rest of the day, they’re not going to do very well,” says Fung. “I know that. I mean, I see that all the time and it’s simply not a powerful enough fast for a lot of people.”
Here’s where things get tricky though. People doing more extreme fasts at the Metabolic Clinic are supervised by Fung and his team. When diet gurus in the wild west that is the wellness world advise DIY extreme fasts, there is a danger of self-harm. For example, I did a seven-day detox program last year for the sake of journalism and concluded that, first of all, it was a starvation diet and, second of all, that starvation diets aren’t my thing.
“Fasting is a tool and you have to know when to use it and, yes, you could do great harm if you use it badly,” says Fung. “Almost everything we do in medicine could cause great harm if you don’t use it correctly. But taking the tool away is like saying knives are bad because you could cut yourself, but, if I want to cut my steak, I need a knife, right?”
I keep coming back to the University of California study and wondering about the definition of insignificant weight loss. If you lost two pounds every 12 weeks, that’d be over eight pounds a year. Nobody aiming to become the “biggest loser” would be satisfied with that, but a lot of people might be quite happy to imagine themselves being eight pounds lighter this time next year. If you did that for a few years…
If it works, that is. And the peer-reviewed research simply isn’t there at this point, so we can’t really say with any certainty. All we know for sure is that fasting for 16 hours isn’t a licence to graze for the intervening eight. Which is also kind of common sense, right?
Science takes time, especially dietary science, because it’s hard to do large control studies and be sure that people are sticking to their experimental regimen for weeks at a time. We will eventually get more answers, though, perhaps even some from University of California’s Weiss, who, even though he’s given up fasting himself, hasn’t written off the regimen completely.
“I’m very intrigued by the interaction between meal timing and diet composition, particularly when it comes to macronutrients,” he says. “So, I’m hoping to do a study in the future where we would look at the potential interaction of the two variables together.”
So, stay tuned. We’ll know who’s right eventually. And on the need for more research, everyone agrees — especially Fung. There’s no need for polarization.
Instead, we need to do more of the thing that seems the hardest for humans — to be patient. Especially when it comes to weight loss.
I think it is important for health to have a long period without eating. Drinking water (unless you’re asleep ) or naturally unsweet beverages (black coffee, matcha tea etc).
However, when you get actual hunger weakness, both the body and the bacteria biome in us need food.
I can only do 12 - 14 hours. Usually only 12. It is what it is. I know the difference between low blood sugar in the morning (caused by eating carbs the previous evening) ( a bit of a sweet tooth feel and which should be ignored) and true hunger, which comes across as a body weakness and a craving for animal protein, and it’s time to eat.
“Science takes time, especially dietary science”
It’s not science when it’s fraught with confirmation bias, and most research is...exactly that.
This is the most sensible article on dietary advice I’ve seen since I abandoned outreach on the topic until I finish my book(s).
Words of wisdom soon to be demonized by those who proclaim otherwise (I’ve met them).
I combine keto and IF. Definitely NOT an eat anything approach. Eat between noon an 6 pm. Lost 35 lbs quickly. Weight has leveled but my waistline has decreased a little over the last 18 months. I’ll never go back to three meals a day.
It works great if you can keep it up.
I have done it for periods of time, but eventually I get lazy.
I average 1,000-1,200 calories a day plus IF (never heard it called that).
I’m down roughly 50 lbs in 15 months (and I’m on my feet several hours a day lot of walking)
I’m down 70lbs from 6 years ago
And yes I had taco bell last night - I had not eaten for 24 hours because too busy
Just weighed myself a few minutes ago
If you’re going to do IF, it’s best to do keto — or something very much like it — to be successful. If you continue eating a lot of carbs/sugars, your blood sugar will yo-yo and you’ll be miserable during the fasting hours. The beauty of keto is that your blood sugar is entirely stable and your appetite is well under control. Done right, IF is a breeze, with weight loss a pleasant side effect.
Try it and see for yourself. No need for pseudo intellectual discussions about it.
“I average 1,000-1,200 calories a day...”
Same here. I also am an “almost” vegan. I rarely eat meat and get my protein from plant-based sources. I’ve been doing this for five years. I also walk 3 to 5 miles a day.
Age = 76
Former cancer patient and a former dialysis patient. I credit the above to my survival and coming off of dialysis.
I’ve done it, but I’ve gotten better results from making sure I have adequate nutrition and supplementing with a good supplement when my diet lacks. Cod liver oil is also helpful this time of year due to containing vitamin D and Omega 3s.
I suspect that a lot of health problems in this country might be due to malnutrition, as crazy as that probably sounds. The last time I fasted I ended up getting sick.
Sounds awesome
Keep it up!
A great book on this and a related topic is Lifespan: Why We Age—and Why We Don’t Have To.
“Should, one day, the entire theory of vitamins be overturned, men will still eat their dinner and feel better for having done so.”
~ C.S. Lewis, Mere Christianity
Although I have been attacked, and name-called by others on this topic in this forum, I still maintain that if input is > than output then one is going to gain weight. If input = output then weight will be maintained. If input is < output then weight will be lost.
In other words, if one fasts and intakes only water then one is going to lose weight, regardless of output, period. I guarantee it!
Agree wit your comment.
Keto or Atkins combined with IF is the best way to go.
You can still eat veggies and healthy proteins. Very doable diet.
I have a simple diet plan... I fast between each meal.
For evening meal, I sometimes instinctively want "only" vegetable + dairy ---- like a big lettuce salad with side of lite cheese, or big bowl of tomato/vegetable soup with rice crackers and add chunks of lite cheddar to the soups. For dessert -- some dried papaya or a fresh fruit, for example.
A few nights a year - I'll only have a big bowl of cereal with milk if I return home late from work - or, a large bowl of plain yogurt with honey and berries mixed in it. BTW, a big bowl of yogurt at night makes for A VERY SOUND & GOOD Sleep -- I recommend that, if you have sleeping troubles.
I take an assortment of multi-vitamins every day as well.
This practice has kept my weight at about 134 as a woman. Men need much more calories & more "beefy" stuff, so not advising this for men.
I'd say the evidence that the conventional advice to eat low fat, carb heavy meals has pretty blatantly failed people in spectacular fashion is crystal clear. Heart disease isn't really down but diabetes and obesity are through the roof. But too many people staked their careers on that advice, their pride has blinded them to the obvious. And that is that on balance another way is needed.
What works to lose weight is suppressing insulin (see the work of Dr Joseph Kraft, among others). Carbs do the opposite, insulin spikes and you get fat if that's your primary form of food. Low carb / high fat spikes insulin less. Fasting doesn't spike it at all, in fact it lets it fall to it's natural level. That's why it works to lose weight. And of course eating less to lose weight is common sense. What they should say, though is that eating less often will result in weight loss. Time is a key factor.
People say though that if you fast you'll die because you aren't getting nutrition. That's false, plenty of evidence on that. Burning your fat stores releases various nutrients and vitamins and the blood work shows it clearly.
Bottom line: people should do what they want but for me, intermittent fasting works and my own health, as indicated by hard measurable factors, has never been better than has since I started eating this way (mostly one meal a day).
I am doing the same. Rarely eat breakfast then my big meal is in the afternoon. Sometimes if I feel hungry after 6 just a salad or vegetable snack.
The first time I tried keto, I lost 20lbs very quickly. Then I broke off keto and went right back up. This go around, I lost 10lbs quickly but now stuck. Not sure what to do at this point.
The best part about keto is no processed foods, few carbs, no sugar and you have to eat a lot more vegetables. That is good advice no matter your diet. It does take time though. It forces you to cook rather than popping something in the microwave.
It is much easier to skip a meal on keto. I find that I many times pass mealtime without any hunger pangs
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