Northern Alberta Institute of Technology

Does intermittent fasting work?

Why, under some conditions, water may be enough

I don’t exactly enjoy eating. At least not in that picture-taking, Instagram-posting kind of way. It’s just something that has to be done to get the energy I need to get everything else done. If there’s one thing about eating that I actually like, it’s not being hungry.

That’s why I can’t imagine choosing to go without it. I did a quick assessment of what I eat, every day, before lunch. It’s more than 1,300 calories. I didn’t tally the rest of the meals (and, yes, snacks). What’s another couple thousand calories when there’s always so much work to do? (There’s also near-daily running involved, I should add.)

Others may not see it that way. These days, intermittent fasting – in which people choose to go without eating for either hours or a day at a time – tends to be a common topic in health and fitness discussions, and ranks high among popular diets. Really? Better living through not eating? More like people slumping on couches and hangrily sniping at each other about what to watch on Netflix.

Curious about the trend, I checked in with Personal Fitness Trainer chair Kate Andrews, who regularly practices intermittent fasting, and NAIT’s registered dietitian, Nick Creelman, who has helped clients who’ve wanted to try it.

Apparently, work need not grind to a halt, TV need not be consumed in excess, and practitioners may not have to go hungry. Done right, intermittent fasting may even have benefits. Though not endorsing it, neither Andrews or Creelman dismissed it outright. Consuming nothing but water for set periods may have its place, whether I like it or not. Here’s what they said.

Why people do it

focus through intermittent fasting

Creelman: If a person isn’t fasting for religious reasons, such as Ramadan or Lent, they’re usually doing so to change their body composition or lose weight. The research does show that it supports weight loss.

Andrews: I think the last reason somebody should want to do it is weight management. One of the main reasons driving me towards it is some of the [other] research. It can really help with cellular cleansing, I guess you could say, or cellular repair [a process also known as autophagy, which removes molecular debris that can interfere with normal functions].

"I do think it's helped with some mental clarity and focus."

And I do think it's helped with some mental clarity and focus, and I like that.

Creelman: Some people say their energy is better than it's ever been, on fasting days. If insulin is not rising and falling, you should have a steady state of energy. You seem to get better blood glucose control. Improvement in the lipid profile [such as a decrease in the “bad” form of cholesterol] has also been found.

What it looks like

intermittent fasting

Andrews: Usually, you fast for 16 hours and then you have an eight-hour eating window, which is pretty user friendly. The way I started is I would just go a little later, a little later.

Creelman: [The 16-8 pattern] is usually going to end up being two meals and snacks. Another type of fasting is alternate-day fasting. The reason the full day seems to work [for those wanting to lose weight] is that most people don't end up eating back that full set of calories over the week.

What could go wrong?

intermittent fasting

Creelman: There can be increased hunger, or hunger pains that come in waves. [They] usually die down.

Mood swings can be a big issue. Some people have a terrible mood – “hangry,” as the term is used.

Andrews: Intermittent fasting can play with your hormones. For females, that can be a big thing. A week or two before menstruation it can be really hard to fast. Obviously, pregnant females or nursing females, no. Anybody who is not generally healthy will want to consult their doctors.

"I would never recommend high-intensity aerobic fitness on a fasting day."

Creelman: I would never recommend high-intensity aerobic fitness on a fasting day because you're just forcing your body to break down muscle to use as fuel.

Andrews: I would eat if I'm working out a lot. If I'm struggling [that day] or if I have a presentation coming up or something like that where I'm a little worried, I would eat. I really play it by how my body feels.

Creelman: People who have a history of disordered eating should never fast.

How to make it work

whole foods

Creelman: Just because you're fasting doesn't mean you don't have to eat good food. We have to get away from ultra-processed foods as much as possible. The average Canadian has 60% to 70% of their calories coming from ultra-processed foods.

How are you going to get all the vitamins and minerals your body needs? Some people think it's as easy as popping a multivitamin. People shouldn't have to pop a multivitamin if you eat the right foods.

Related: Dietitian Nick Creelman busts common nutrition myths, in the podcast

Andrews: Just really focus on getting those real, whole foods in, and reducing sedentary behaviour.

The skinny on intermittent fasting

intermittent fasting

Creelman: It's not greater than anything else. But it could be an easier option for some people. The rules are easier [than other diets]: You eat or you don’t. But for weight loss and body composition, it's no better than a traditional calorie-restricted diet.

"It's no better than a traditional calorie-restricted diet."

Andrews: I think about how my [hunter-gatherer] ancestors lived for generations, and it makes sense that they didn't eat for awhile. Our genes have adapted to that.

And you know what? Even as a kid, I never wanted to eat breakfast. My mom had forced me, to the point where she finally would give me a Carnation Instant Breakfast. In the end, it probably would have been better for me not eating then some of the additives that were in that.

I still think, is it better to eat badly or not at all for a period? I still have breakfast. I just have it at 11 a.m.

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