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Discover: Is intermittent fasting the weight-loss cure people think it is?

The jury’s still deliberating on that question, but the more we study intermittent fasting, the more we learn it doesn’t just impact weight
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The word ‘fact’ has been more than a little abused in recent history, but for those who respect the power of the fact, their consistency and dependability can be a balm, a warm hug of stiff impenetrability, a wall against those who would attack you.

Or, they can sit on your chest like a gorilla.

These weight loss facts are the latter. Terribly sorry to have to do this to you, gentle readers, but we better just rip the Band-Aid off. If it helps, these come directly from Jeffrey Gagnon, associate professor and chair of the Biology Department at Laurentian University, whose field of study is medical endocrinology (during an interview that was followed directly by the interviewer taking a very long, very brisk walk).

  1. The root causes of obesity are created before you have any say in the matter whatsoever. Even before you were born.
  2. Your fat cells never leave. If you lose weight, the fat cells do not disappear, they shrink. These cells just wait within you, hoping to get bigger. Actively trying to get bigger. Which leads us to:
  3. If you lose weight, you must continue the mechanism for your weight loss for the rest of your life, otherwise the waiting/weighting fat cells will engorge.
  4. This one hurts. So much so that Gagnon needs to say it first: “Anybody can lose 20 per cent of their weight – if you focus on it. Five years later, if you’ve still got five percent of that weight off, you’re outside the norm. This is a big success.”

That is to say that successful weight-loss mechanisms, diets really, are measured not by the amount of weight a person loses, but by how long they lose it for. If you are able to maintain that weight loss, it is sustainable for you, then that is a successful diet. What Gagnon’s quote reveals is that if you are 200 pounds and you lose 20 per cent (or 40 pounds) you are now 160 pounds. If, in five years, you weigh 190 pounds (ten pounds from your old weight, but still five per cent below) you are considered a great weight loss success story.

And of course, many people have stories about neighbours and friends who have lost weight and kept it off – because there are always outliers – but that could be more about the stories we choose to tell, versus the ones we do not. A classic case of remembering the hits and forgetting the misses.

So now is talk of another diet, one known as intermittent fasting (IF). With all the above caveats in place, it is time to talk about scientific studies, weight loss, glucose metabolism, and how stressful eating can be.

Intermittent fasting is a form of calorie restriction, but instead of a daily reduction in calories – as in, you move from eating 2,000 calories per day to 1,500 per day – this is a restriction in the time of each day, or each week, that you consume calories. It is a calorie-restricted diet in that you are limiting the hours in which you consume calories.

There are many fasting schedules you can try, but here are the four main ones: 1. Alternate day fasting (consuming no calories whatsoever, every other day, then eating as usual on the non-fasting days); 2. A modification of this wherein participants consume calories on the usual fasting days, but less than 25 per cent of what they normally would; 3. Time-restricted fasting (restricting calories intake to specific times during the day), and; 4. Periodic fasting, a fasting that takes place for one or two days at the participant’s discretion, often an occasional fast, or a weekly personalised version like five days of eating, two days of fasting.

Time-restricted fasting appears to be the most achievable, and most popular, type of fasting schedule. That said, according to a small and short-term study, there is not really a statistically superior fasting schedule.

And now, to the nitty gritty. While IF is still somewhat new in research circles, it has come to a point that a meta-analysis, published by the open access journal, the Journal of Clinical Medicine, has been created. A study or studies, if you will. 

The meta-analysis examined the studies available on intermittent fasting on individuals who had no chronic diseases affecting glucose metabolism (like diabetes) and applied rigorous analysis to the quality of the studies performed – so much so that out of the 2,814 studies they found in their search, only 12 studies made the cut. 

As well, they add the additional issues that crop up with such studies: dietary studies are notoriously difficult to conduct, with the reliance on self-reporting and adherence to study from participants and often small groups of people over short periods. In fact, the current crop of studies only extended as far as four to 24 weeks.

But even with these challenges, there were remarkable findings. Not so much for weight loss, although there was that, but in the other effects that IF can have on the body.

Yes, studies are showing weight loss while fasting intermittently. Not that much, compared to other diets, and it’s most likely because participants are consuming fewer calories. 

Per the meta-analysis: “No significant weight loss was observed in studies that adjusted the fasting time while maintaining total calorie intake. Thus, the main pathophysiologic mechanism of weight loss through an Intermittent Fasting Diet is likely to be a reduction in calories.” 

As well, this should be considered in addition to the gorilla-sized facts from the beginning of this article.

But the interesting aspects of fasting come from our understanding of the endocrine system (a collection of glands producing hormones that regulate metabolism, growth and development, tissue function, sexual function, reproduction, sleep and mood), and the stress of consuming calories.

The meta-analysis found that there was an improvement in fasting blood glucose and insulin resistance through IF as compared with a non-fasting control group. To understand why that may be – with heavy emphasis on the ‘may’ – we need to understand our stomach, the largest endocrine organ in the body.

The stomach produces our hunger hormone, called ghrelin, and our colon produces most of a hunger-supressing hormone called Glucagon-like Perptide-1 (GLP-1).

Ghrelin is a recent discovery (2000) and is the hormone responsible for your hunger pains, nausea and other ‘you must eat’ indicators, like ‘hangry.’

But unlike sleep, which runs with circadian rhythms, ghrelin begins because that is the time you usually eat. We essentially ‘train’ our system to tell us when to eat, based on when we ate before. And so, if you don’t eat, your body insists upon it, very strongly, with rising levels of ghrelin that can actually be measured in the blood. 

When someone restricts their eating periods — refusing to listen to the insistent ghrelin, in effect  — then they can actually begin to blunt its effects, making it slightly easier to fast.

When you do eat, the ghrelin production crashes, and is immediately replaced by GLP-1, an appetite suppressant that shuts off the body’s processes to insist you eat.

Ghrelin was highly researched at first due to its potential for fighting obesity – to shut off the hunger hormone. But it didn’t work so well (somewhat like those older commercials that mentioned ‘leakage’ (from a certain area). It is now being pursued as an appetite stimulant for treatment of wasting diseases and cancer.

GLP-1, however, is now a treatment for Type 2 diabetes, and for morbid obesity. And this is perhaps where the influence of intermittent fasting on glucose and insulin could be found. But again, the research is still unclear.

But the stress — and no, not just choosing what is for dinner — is another avenue of IF worthy of further study as it relates to the oxidization of the body. Free radicals, anyone?

“When you ingest calories, particularly fats and energy-dense things like refined sugars and saturated fats, it’s like throwing a lot of fuel into the furnace,” Gagnon said. “The wood stove in this metaphor is going to be the mitochondria of your cell — from a cell biology background that’s like the main furnace in your cells ... that’s the thing that’s taking all of these fats and carbs and different things and making energy for your body.”

To continue the furnace analogy: “And so if you jam in a ton of gas-soaked wood, it’s going to get really, really hot.”

This overly-intense mitochondrial stress creates cellular stress, and that cellular stress causes the cells to oxidize. This is the cause of Reactive Oxygen Species: unstable molecules that easily react with other molecules in a cell. Too many of these in cells may cause damage to DNA, RNA, and proteins, and may cause cell death. Reactive oxygen species are perhaps more commonly known as free radicals.

If you reduce that stress with fewer energy-dense (but not necessarily nutrient dense) calories, what happens? 

“As you reduce oxidative stress in your body from eating, you start to get cell functionality back … something like insulin resistance,” Gagnon said. “That’s a common thing that happens in Type 2 diabetes: you make insulin, but your cells are kind of like ‘yeah, I know it’s here but I don’t really care’. That’s partly caused by oxidative stress. So if you take out the stress — the reactive oxygen species out of the individual — then you might start to get that insulin sensitivity back.”

But for all the talk of potential health benefits, fasting isn’t easy. It not only requires an overabundance of research, but also requires the faster to overcome a complex wave of redundant systems. Your body wants you to feed it and has multiple mechanism for getting that message across.

“If one system in our body fails to stimulate hunger, there’s redundancy,” Gagnon said. “There are many other hormones, there are other pathways that will take over and ensure that you are going to find food, and you’re going to drive yourself to go and find food. Even if you block ghrelin, something else is going to pick up the slack.”

Additionally, all of modern society, including family and celebratory events and even workplace

schedules, are built around prescribed eating at prescribed times.

But if you are able to overcome the ghrelin – and other systems – then there could be potential for health benefits in intermittent fasting that extend beyond any short-term weight loss. Do your research, follow the advice of trained professionals, and continue to track the research as it comes available.

But for right now, there isn’t much.

There is research, however, into the importance of a holistic approach to the obesity crisis. New

guidelines released by Obesity Canada and the Canadian Association of Bariatric Physicians and Surgeons advises health care workers that any talk of weight loss needs to focus on root causes, not any pre-conceived notions of ‘fat’. 

“Working with people to understand their context and culture, integrating their root causes, which include biology, genetics, social determinants of health, trauma and mental health issues, are essential to developing personalized plans,”said Dr. David Lau, co-lead author of the guidelines and professor at the University of Calgary.

From his point of view, and Gagnon’s, it’s about understanding yourself first, and learning to understand your body after. 

“Get yourself to a place where you feel good; you’re healthy, and you’re under control,” Gagnon said. “And if that means you still have a little bit of weight, that’s awesome – own it. You know that you’re healthy, and eventually, the less we stigmatize, maybe society will come around.”

And so, once again, the answer to a diet question is: simple, complex, and a good pinch of I don’t know.

Jenny Lamothe is a freelance writer and voice actor in Greater Sudbury. Contact her through her website,