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15 October 2020 | by Aadam
It’s Thursday which means it’s time for another instalment of the Vitamin. Every week I drop some knowledge bombs on your face to help you get to your goals quicker while avoiding all the misinformation.
Let’s dive into this week’s issue.
1) I follow someone on IG who had a very interesting post, and because I trust your opinion I wanted to get your take on it. This person posted saying that we should not be eating every 2-3 hours, we should wait for our body to naturally tell us when it’s hungry. And when we eat, we should eat a meal, not snacks, so we have a feeling of fullness. She also backed this up by saying a meal boosts the release of leptin better than snacks…which would suppress your appetite longer. I have always been a “eat every 2-3 hours” type of person, and wonder if you think there is any benefit to only eating 3 meals a day?
Eh, this advice isn’t entirely wrong, but it’s more wrong than it is right.
For one, it’s way too much of a generalisation. Some people find eating every few hours actually helps them control their hunger better, which improves adherence. I’ve worked with many clients who would eat very little during the day (e.g., due to a busy schedule) and then overeat by huge amounts at night. By getting them to eat more frequently, they stopped overeating because they weren’t coming home absolutely famished.
For two, the person claims we “should wait for our body to naturally tell us when it’s hungry.” Ok, cool. Small problem, though: What happens if someone eats breakfast at 7am and then gets hungry at 11am, but lunch is still four or five hours away? This person’s body is “naturally” telling them they’re hungry, now what? Do they listen to their body and eat and risk eating more than 3 meals, or do they ignore their body and just power through until lunch?
For three, in the short-term, high or low leptin levels don’t affect hunger. This was illustrated in a 2015 study by Chowdhury et al. that found people who skipped breakfast had lower levels of leptin than breakfast-eaters, but both groups reported similar levels of hunger. (Additionally, there’s more to hunger and satiety than leptin.)
Lastly, the type of snacks people eat will also influence satiety. For example, high-protein, high-fibre snacks will be more satiating––and can actually reduce calorie intake at the following meal––than snacks that are high in fat, sugar (and calories).
With all of that said, eating fewer meals per day can be beneficial in certain cases. For instance, 1500 calories per day would be 250 calories over five small meals or 500 calories over 3 large meals. A 500 calorie meal would help keep you satiated longer than a 250 calorie meal because, you know, you’re eating more food.
This was an insanely long way of saying: eat however many meals you want, you enjoy, and can stick to.
2) I’m being sent away to a small rural town, for my clinical placements, for 8 weeks. I won’t have access to gym and gym equipment (dumbbells etc). Will I reverse all the muscle gains I’ve made if I didn’t train for 8 weeks? What’s the best I can do in this situation, in terms of training and diet?
I’ve discussed this in detail here.
But, in short, as long as you’re consuming enough protein and providing some form of stimulus to the body––like bodyweight training––you should be able to maintain the progress you’ve made.
– How a Lack of Sleep Is Ruining Your Progress
Everyone––whether or not they understand why––intuitively knows that a good night’s sleep makes you feel on top of the world, capital A awesome, and like you can stop a speeding bullet with your bare hands. A poor night’s sleep, on the other hand, makes you feel capital S shitty, and even completing simple tasks can feel Sisyphean.
And it wouldn’t be an exaggeration to say that sleep is just as important as your training and nutrition. In fact, seeing how much of an influence sleep has on both of these things, maybe even more important.
One of the ways a lack of sleep cockblocks your body composition goals is by increasing hunger and cravings.
A 2017 review by Al Khatib found that, compared to participants who slept ~7 hours per night, participants who slept less than ~5 hours per night consumed 385 more calories per day, with more of the calories coming from an increase in fat intake.
Zhu et al. (2019) found that sleep restriction increased subjective hunger, and the sleep-deprived participants consumed ~250 more calories per day than the participants who got enough sleep.
And more recently, a review by Fenton et al. (2020) found that sleep duration restricted to <5.5 hours per night led to a mean increase of 204kcal/d.
The same review also offered some explanations as to why sleep restriction increases food intake.
1) Sleep restriction disrupts appetite hormones(?)
There are two hormones that control appetite: ghrelin and leptin.
When ghrelin levels increase, it triggers a strong sensation of hunger; conversely, when leptin levels increase, it blunts appetite.
Some studies have found that short sleep duration lowers leptin while increasing ghrelin which, in turn, increases hunger.
Though, it’s worth pointing out these were observational studies and can only establish correlations, not an actual cause or effect. This is why newer studies are contesting the ‘hormone hypothesis’ (i.e., ghrelin/leptin) as the sole reason poor sleep can lead to increased food intake.
Markwald R et al. (2013), for instance, found that sleep-deprived people ate more food despite an increase in leptin and decrease in ghrelin.
Chaput et al. (2014) agreed with these findings noting that yes, insufficient sleep does increase calorie intake, but this is due to other factors unrelated to ghrelin or leptin (more on these factors below).
And the meta-analysis by Zhu et al. I referenced earlier also didn’t find strong evidence to support sleep loss influencing leptin (11 studies) and ghrelin (13 studies) levels.
So, if it’s not these hormones that cause people to eat more when sleep-deprived, what does?
2) More time and opportunities to eat
This one’s pretty obvious––the longer you’re awake, the more time and opportunities you have to eat, which, if not consciously controlled, can lead to increased food intake.
3) Greater sensitivity to food reward
Some studies have found that sleep restriction activates brain regions associated with food reward.
St-Onge MP et al. (2013) demonstrated that sleep-deprived individuals (4 hours of sleep) saw greater activation in these brain regions when presented with “unhealthy” foods compared to “healthy” foods. This effect vanished once the participants got enough sleep (9 hours).
4) Lowered dietary restraint
If you’re sleep-deprived, then trying to make good choices is often harder, especially when you have hundreds of other things vying for your attention. Sleep loss can also increase impulsiveness so instead of making the decision that will benefit you the most, you tend to choose immediate gratification. (Krause AJ et al. 2017)
One last thing that’s worth mentioning is that there are individual differences, and sleep loss doesn’t always lead to an increase in energy intake. The evidence for the ‘hormone hypothesis’ is fairly weak, and as you can see from the list above, the majority of these factors are all things you can control to some extent.
The first (and the most obvious) thing you should do is fix your sleep habits. Get into bed at a time that will allow you to get at least 6-9 hours of sleep per night. Don’t play with your phone in bed, don’t consume caffeine or alcohol too close to bedtime, and make sure that your room is the right temperature (not too hot).
For many people, just fixing their sleep habits automatically improves sleep quality. And not only will this help you be healthier, more energised, and focused but you’ll make better progress with your fitness goals.
– Scale Fluctuations Are Annoying––Here’s What’s Going On
If I had a pound (or dollar) for every time someone freaked out about their scale fluctuations, I’d be the richest man alive, and instead of writing these weekly emails, I’d be living on a mega-yacht partying my face off. Lol, joke – I despise parties with a furious passion, and I can’t swim so that would be my definition of hell. Also, sharks.
But seriously, read this damn article to understand why scale fluctuations happen and why they’re totally normal.
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