24-hour fasting experiment

What is fasting?

In simple words, fasting = not eating. There are several of protocols used as therapeutic fasting or fasting-mimicking diets (e.g. intermittent fasting, alternate day fasting, calorie/protein restriction).

Why fast?

There have been many experiments conducted in all sorts of critters (from yeast to humans) to study the impacts of fasting. Results from both non-human and human studies suggest that fasting could extend lifespan, reduce oxidative stress and inflammation, prevent neurodegenerative disease, improve cognition, reduce cancer growth and enhance metabolic function, among other health benefits. The mechanisms behind those effects include the production of ketones and their role as an energy source for the brain, the reduction of blood glucose and insulin, and the stimulation of apoptosis (programmed cell death) and autophagy (cellular cleanup process).

The aim of this post is not to cover all aspects of fasting therapies, but to report on my n=1 experiment. If you’re interested in learning more about fasting/fasting-mimicking diets, here are some resources:

On to the experiment

I have been thinking about doing this experiment for a few years but life always got in the way. The opportunity presented itself when my husband had to travel for a job interview (I find it easier to experiment with my diet when he’s not around).

My last meal was Sunday lunch. I had had neck and shoulder pain for a few weeks, so I went for a massage, then came back home, watched a documentary and did some work. I drank several cups of warm water and didn’t feel hungry until 20:30ish. I did a short meditation, prepared my stuff for the next day and went to bed around 21:30. I was expecting having trouble falling asleep due to:

  • Not having done any physical activity
  • Being slightly hungry
  • Having trouble sleeping when my neck hurts
  • My personal heater (i.e. husband) being away

I was awake until 3:00. My alarm buzzed at 6:00, so I had a grand total of 3 hours of sleep. I tried to go back to sleep but couldn’t, so I decided to get up and go on with my day.

I got to work half hour earlier than usual. By then I could recognise the signs of full ketosis: a clear brain and low body temperature. Hunger came and went but didn’t last long. I contemplated having my morning coffee as per usual (after all, it has negligible energy and zero protein) but decided to stick to water.

The hardest part, surprisingly, was not flicking through Instagram food photos, but smelling my coworkers’ lunches around noon. I normally eat at noon but this time I had to wait until 13:00 to complete the 24 hours. I’d say the last hour was probably the hardest, also because I finished the work I was doing so had nothing pressing to keep me distracted. I ate my lunch plus a few handfuls of macadamias sprinkled with sea salt not because I was hungry, but to make sure I was making up for some of the calories that were not consumed during the experiment. I kept drinking water throughout the day.

That night I did a Krav Maga class as per usual, and surprisingly didn’t feel any shortage of energy nor strength, despite having slept only 3 hours and eaten just one meal within the previous ~30 hours. The lack of sleep didn’t hit me at all, but I’m not sure if I can attribute this to fasting.

Parting thoughts

From what I’ve read, I think there is compelling evidence to suggest fasting once in a while is beneficial. It makes sense that lack of energy intake would elicit a hormetic response and allow cellular cleaning processes to occur. It also makes sense from an evolutionary perspective that we should not have food in our bodies 24/7.

My plan is to implement fasting periods of varying durations whenever there is an opportunity (e.g. travel, periods off training such as dealing with injuries, etc.).

Food for thought: Moderation for the moderators

If I had 10 cents for every time I’ve heard “everything in moderation”… Actually, it’s more like if I had 10 cents for each time I’ve said it (read: I’m broke). Unlike most dietitians, I don’t advocate moderation because I don’t think it’s the right thing for everyone.

As Gretchen Rubin has noted, there are 2 kinds of people when it comes to behaviour: moderators and abstainers. Moderators find it easy to have 1 square of chocolate whenever they feel like it; abstainers demolish the whole bar if it’s within reach. Needless to say, the strategies that work for each type of person are different.

I’m an abstainer and that’s why I find it easier to create rules for myself and stick to them. I now understand that I can’t ask everyone to do the same, but I can suggest people like me to try using similar strategies.

Craig Ballantyne, whose work on the fitness industry has helped me in the past, also works in the world of habits. I’ve heard him say many times that rules make life easier because you become a person who behaves a certain way all the time, which avoids wasting time fighting against oneself. I agree with this principle, but would add that it only works if you are the kind of person who can stick to rules (typically abstainers, in Gretchen Rubin’s terms).

The other problem with moderation, in my opinion, is that there is no definition or limitations as to what constitutes moderation. From what I’ve seen, people who advocate for moderation normally consume a lot more of crap than what I would consider a moderate amount. Moderation becomes an excuse to overdose on things that they know they shouldn’t be having. I think that it’s helpful to record what you eat in a day (or a few) to have a clear picture of your diet. You might find that what you call moderation looks a lot more like excess.

Final rant: nutritional guidelines typically do not reflect “everything in moderation”. This and other mixed messages are, in my opinion, why there is so much confusion in the topic of nutrition.

Food for thought: For most questions the answer is “it depends”

A person concerned with her weight recently asked me and another dietitian how much avocado she could eat per day. As always, my answer was “it depends”. Without a context (what does her current diet look like, does she have any medical conditions, what is her metabolism like, etc.) it’s impossible to answer that type of question with a round (or decimal) number.

This reminded me of something that happened more than 10 years ago. I had lost some weight and some girls at work started eating apples with lemon juice (on top of their normal diet) because someone had seen me squeezing lemon juice on an apple (most likely to prevent oxidation) and they assumed that that was the key to weight loss. A great example of how correlation does not mean causation.

Most people are after the magic pill, the ultimate superfood, or the perfect supplement; the ultimate shortcut to optimal health or body composition. The problem is that health is incredibly complex and, in addition, a moving target. I prefer to approach health as a continuum rather than a binary switch. The same principle can apply to foods and lifestyle choices, which are typically more or less healthy for a particular person than an alternative, and not necessarily “healthy” or “unhealthy” per se. My “healthy” can be your “junk”, or vice-versa.

Intermittent fasting (IF)

Earlier this week two of my friends mentioned an article on intermittent fasting published by a local newspaper. Apparently mainstream media had just heard the news.

Intermittent fasting (IF) is not a new concept my any means, people have been fasting forever (our ancestors didn’t have access to food 24/7, and religious fasting has been around for a long time) and science has been running studies on the topic for decades. However it took a while for it to become “popular” in the nutrition/fitness circles. The first time I heard about it was 2007, but I didn’t pay much attention to it perhaps because the stuff that I read was a commercial program aimed at weight loss only. When I learned about all the health benefits associated to fasting I was keen on giving it a go.

Empty plate

So a couple of years ago I began by “scheduling” my fasts on non-lifting days, but I quickly realised it was not a very natural way of doing it. Granted, intermittent does not mean random but in my experience random works best for preventing adaptation (which BTW is why it’s a good idea to vary your training). So I ditched my plan and now just let it happen when it happens, for example when I’m not hungry in the morning, or when I fail to wake up on time and have to run in the office.

What happens when you fast? Basically your body switches from using sugar for energy to using fat, similarly to what happens with ketogenic (high fat, very low carb) diets. Therefore, your insulin sensitivity increases. Your body’s garbage collector (an analogy for my software development colleagues) turns on and recycles waste products in a process called autophagy. And many other benefits that you can read about on the links below.

On a practical level, this is what I get out of it: my thought process is clearer, I feel lighter, more awake and energetic. The occasional bout of hunger (usually triggered by reading food blogs) goes away quickly, mainly as a side effect of eating a nutrient-rich diet. On the flip side, I tend to get colder than usual, with a “minty” feeling on my skin.

So, does that mean that everybody should be doing it all the time? Well, no. As Robb Wolf often says, intermittent fasting is a tool, like many others. Sometimes you need a hammer, sometimes a screwdriver. It can help some people at certain times. Stefani Ruper has analysed the effects of IF in women in depth (see link below). Right now I’m only doing it very sparingly, and never when uni is on, because juggling study and work is stressful enough.

Note: while the article does a good job in introducing lay people to the topic, I find their meal plan suggestions rather disconcerting. They recommend having breakfast, lunch and dinner (where’s the fasting? in between meals?) based on the premise that “The best thing about this diet, I decide early on, is that fasting doesn’t mean not eating. It means eating very little.” Well… not really. Mat Lalonde says you can get the benefits of autophagy if you eat something apart from protein. I would assume it’d be better to stick to a ketogenic protocol (coconut oil, maybe some nuts or avocado, salad greens, etc.). Still, authophagy is only one benefit of IF, and I don’t imagine all of them would be present by almost fasting. Specially if you’re eating toast, baked beans, yoghurt, fruit, steak and salad, as the article suggests. They’re basically recommending a calorie restricted diet, with no real fasting going on.

For more information on the topic please check the following links:

The Myriad Benefits of Intermittent Fasting, by Mark Sisson
“…fasting once in a while seems to offer many of the same benefits of calorie restriction – you know, stuff like increased longevity, neuroprotection, increased insulin sensitivity, stronger resistance to stress, some cool effects on endogenous hormone production, increased mental clarity, plus more – but without the active, agonizing restriction.”

My Times Piece On Intermittent Fasting by Dr John Briffa
“On days where you’re intake of food is significantly reduced, it pays to emphasise foods that are highly nutritious and effective at sating the appetite. Protein and fat tend to pack most punch here, so appropriate foods might be fresh meat, oily fish, eggs and nuts, coupled with some green vegetables and salad for additional nutrients… Intermittent fasting has merit, I think, but it’s not for everyone. Those who should avoid intermittent fasting include individuals with a history of eating disorder and diabetics. Other individuals who are generally unsuitable candidates for intermittent fasting include those who are generally ‘stressed’ or have chronic fatigue. Stress can weaken organs known as the adrenal glands, and intermittent fasting can weaken these glands further, which may exacerbate symptoms such as fatigue.”

Experiments with Intermittent Fasting, by Dr John M Berardi
with Dr Krista Scott-Dixon and Nate Green

“Trial fasting is a great way to practice managing hunger… More regular fasting isn’t objectively better for losing body fat… More regular fasting did make it easier to maintain a lower body fat percentage… Intermittent fasting can work but it’s not for everyone, nor does it need to be. In the end, IF is just one approach, among many effective ones, for improving health, performance, and body composition.”

Shattering the Myth of Fasting for Women: A Review of Female-Specific Responses to Fasting in the Literature by Stefani Ruper
“Many women find that with intermittent fasting comes sleeplessness, anxiety, and irregular periods, among a myriad of other symptoms hormone dysregulations. I have also personally experienced metabolic distress as a result of fasting, which is evidenced by my interest in hypocretin neurons… Hypocretin neurons are one way in which intermittent fasting may dysregulate a woman’s system.
…I was struck by what seemed like an egregious sex-based oversight in that MDA post I linked to above. MDA cites this article as a “great overview” of the health benefits of intermittent fasting. This startled me because the article MDA cited was for me one of the strongest proponents of sex-specific differences in response to fasting. This occurred in two striking areas: a) women in studies covered by the review did not experience increased insulin sensitivity with IF regimes and b) women actually experienced a decrease in glucose tolerance. These two phenomena mean that women’s metabolisms suffered from IF. The men’s metabolisms on the other hand improved with IF across the board.”

Strategies for surviving the holiday season with minimal damage

Christmas cake

Image: Filomena Scalise / FreeDigitalPhotos.net

With the holiday season almost here it makes sense for us mesomorphs and endomorphs to start thinking about how to get to the 2nd of January with minimal damage. For those who don’t know what I’m talking about, you should have paid attention to your science teacher in school. I mean, the ectomorph/mesomorph/endomorph classification has been around for decades (in fact, it’s older than me). But still, if you know but have forgotten, simply put: ectomorphs are people who have a hard time gaining weight, endomorphs are people who gain weight pretty much just by breathing and mesomorphs are people in between. That means that for mesos and endos, holiday season is a nightmare because it’s very likely that we fall off track and gain some weight and/or body fat.

I’m not a nutritionist (although I hope to become one in a hopefully near future) but I did study nutrition at cooking school and spend a lot of time reading about the topic. There is great advice out there but you gotta take it with a grain of salt. Nowadays almost every health/nutrition/fitness claim is backed up by scientific research, which can be flawed. Research is often sponsored by companies that want scientists making positive claims about the products they sell. Even if a study is completely independent, science often looks at isolated components of a whole and that doesn’t compare to our “real” lives. So what often guides me towards a worthwhile piece of advice is common sense. I ask myself it the person giving the advice is a good example of whatever they’re talking about. You wouldn’t buy facial products from a person with pimples, would you? I also check out references from that person: do they have support from known and respectable people or organisations? Finally, if practical, I test on me. I think we’re all grown ups and we can figure out what works for us and what doesn’t, because even if somebody claims that cause X will lead you to result Y, we’re all different and we might get different results.

It’s pretty clear by now that this post is not like my usual ones. It’s more like a small contribution to people like me who don’t want a negative effect on their bodies by the end of the year. And it’s also for me. It’s a fact that you learn more by teaching than by receiving a lesson. So this is my way of pushing the theory a bit more deeply into my brain to make it work in auto-pilot. I’ve compiled these tips over the years from a number of sources (John Berardi and the Precision Nutrition team, Alwyn Cosgrove, Craig Ballantyne, Marion Nestle, Michael Pollan, among others). And again, even when they work for me they may not work for you, but you can give them a shot.

  1. Avoid
    You will read everywhere that the key to keep your body composition under control is to avoid empty calories (beverages other than water and unsweetened tea/infusions, sweets, etc) and, in general, the overload of calories that happen this time of the year. I go a step further and say: avoid the circumstances that put those foods in front of your face. If you’re like me, it’s hard for you to refrain yourself from eating/drinking something if it’s right in front of you. It talks to you and calls your name, and that is hard to resist. One of the greatest pieces of advice on this topic is to toss all processed foods from your home. If they’re not available, you won’t eat them, and if you’re lazy enough you won’t bother in going to get some and will stick to healthy foods. So the trick is to avoid situations in which you know there will be snacks and drinks, in my case that would be Thursday nights after meditating with friends and Friday afternoons in the office.


    Image: FreeDigitalPhotos.net

  2. Prioritise and choose
    Of course we can’t spend our lives avoiding social situations. I mean, we could but that probably wouldn’t be so psychologically healthy. What to do, then? Prioritise the events you have during the week and choose just one or two. For example, I’m going tomorrow to Metallica’s show (I’m not a huge fan anymore but they didn’t go to South America when I was younger so I’ve never heard them live). I know I’m gonna have to eat something there and chances are that it’s not gonna be healthy. Then my sister and I will have lunch with Latin American friends on Sunday. That means lots of food (at least, homemade). So this week I decided to skip drinks after meditation on Thursday, and drinks after work and dinner out on Friday. I think the key here is planning, and that’s easy if you’re fully aware of your schedule.

  3. Stop making excuses
    We humans are big on excuses. We have one or many perfect excuses for everything that means a little extra work. I think it’s fine to excuse ourselves from eating a bit of unhealthy food in events we can’t avoid, but come on. The fact that the end of the year is around the corner is not an excuse to skip workouts. Or to stuff yourself with whatever sweets you can get your hands on. Anything is a good enough excuse for being unhealthy.

  4. Think before you act
    This advice applies to many things in life, but now I’ll focus on food. Before eating or drinking something take a few moments to think about it. Most of the times we eat without even being hungry. If you’re not hungry enough for eating an apple or a cup of steamed broccoli, then maybe you aren’t hungry after all, right? If you think that approach is a bit too extreme try this other one: is what you’re planning to eat something you absolutely love? If not, better save those calories for later. Also think of everything you do and eat in terms of an aid or an obstacle in relation to your goals.

    Dessert and coffee

    Image: Daniel St.Pierre / FreeDigitalPhotos.net

  5. Know what you want
    Speaking of goals, I think most people don’t know what theirs are. They clearly have goals, because there’s an intention in everything they do, but they just don’t know them. For some people is good to have proper goals (that is, clear, achievable and measurable), for some is better to focus on the process instead of the goal (for example: to do some kind of exercise every day and eat healthily 90% of the time, instead of to drop 10 pounds by next Friday). Whichever approach you choose, make sure it’s clear for you and remind yourself from time to time.

    Goals dilemma

    Image: jscreationzs / FreeDigitalPhotos.net

  6. Get enough water and sleep
    Water and sleep are two of the best weapons you can use against many things: hangover, headache, stress, the flu, lack of energy, etc. Plus, you’ll save money (think of the hundreds of dollars people spend on drugs, supplements, energy drinks, coffee, etc) and will help you with point # 1 (by drinking enough water you’ll avoid ingesting empty calories and by focusing on getting enough sleep you’ll avoid staying late for drinks and nibbles).

    Drink enough water

    Image: Andy Newson / FreeDigitalPhotos.net

  7. Choose and use the carrot or the stick
    Am I the only one who gets a sexual connotation from that phrase? Maybe it’s just a language thing. Anyways, some people respond better to the carrot (motivation) and others better to the stick (punishment). Know what you like and use it. Here’s an example: you’re in Norton St Grocer surrounded by panettones of all sorts (gianduia included). If you’re a carrot kind of person, remember a nice comment you have received about your physique and refrain from buying one. If you’re a stick kind of person, remember that sad feeling you get every time you look at your bloated belly after eating too many carbs.

  8. Cook more
    Even if that means eating out more and having less material for your foodie blog. If you cook more (aim to weekdays, at least) chances are you’ll eat healthier food unless you are like that lady in Jamie Oliver’s show that deep-fried everything. I mentioned weekdays because I know for most of us is harder to cook on weekends when you get to hang out with friends and family, and relax a bit with a “cheat meal”. As Michael Pollan puts it in his Food Rules: seconds and sweets only on days that start with “s”. Also, when invited to an event, offer to bring something, cook it yourself and try to make it healthy.

I’d like to close this post with a great quote I read in Alwyn Cosgrove’s blog long time ago: “It’s not what you eat from Christmas to New Years, it’s what you eat between New Year’s and Christmas that counts.”