What Sugar Actually Does To Your Brain And Body

What Sugar Actually Does To Your Brain And Body

We consume an enormous amount of sugar, whether consciously or not, but it’s a largely misunderstood substance. There are different kinds and different ways your body processes them all. Some consider it poison and others believe it’s the sweetest thing on earth. Here’s a look at the different forms of sugar, the various ways they effect you, and how they play a role in healthy — and unhealthy — diets.

Of course, if you already know how sugar works and how your body uses it, feel free to skip down to the final section about healthier sugar consumption.

The Different Types of Sugar

There are too many types of sugar (and, of course, sugar substitutes) to tackle in a high-level overview like this one, so we’re really only going to look at the two (and a half) that you regularly encounter: glucose and fructose.


But glucose isn’t perfect. There are many processes involved when you consume glucose, but one that occurs in your liver produces something called http://en.wikipedia.org/wiki/Very_low_density_lipoprotein (or VLDL). You don’t want VLDL. It causes problems (like cardiovascular disease). Fortunately, only about 1 out of 24 calories from glucose that are processed by the liver turn into VLDL. If glucose were the only thing you ate that produced VLDL, it would be a non-issue.

Sucrose and High Fructose Corn Syrup (HFCS)

in a higher production of uric acid and a lot of other things you don’t want

On top of that, fructose consumption negatively changes the way your brain recognises your consumption. This is because your brain resists leptin, the protein that’s vital for regulating energy intake and expenditure (which includes your keeping your appetite in check and your metabolism working efficiently). As a result, you keep eating without necessarily realising you’re full. For example, a soda containing high amounts of fructose (which is most non-diet sodas) will do little to make you think you’re full even though you’re taking in large amounts of calories. Your brain doesn’t get the message that you really consumed much of anything and so it still thinks you’re still hungry. This is a very, very basic look at part of how fructose is processed and doesn’t even touch upon many of its other problems, but identifies the issue most people care about: fat production.

This isn’t to say fructose is all bad. It does have a practical purpose. If you’re a professional athlete, for example, it can actually be helpful. HFCS actually repletes your glycogen supply faster, which is useful when you’re burning it off, so the use of HFCS in sports drinks actually has a practical purpose for those who can quickly burn it off. It’s not so helpful for those of us whose life focus is not physical activity — unless we find ourselves in a situation where we need fast energy that we’re going to quickly burn off.

Processed vs Unprocessed Foods

So why not keep the fibre (or at least some of it)? Because when you process food, you’re not processing it for the purpose of eating immediately. Instead you’re processing it to ship all over the country, or even the world. To do this, you obviously can’t let the food expire or it will be useless when it arrives. Because fibre causes the food to go bad much faster, it needs to be removed.

Photo by Dee’s Illustrations

Additionally, many processed foods are even worse off because of their low fat content. Sure, low fat content sounds good, but just because you eat fat doesn’t mean you retain it. Your body can efficiently process and excreted fat, so fat intake isn’t a huge issue by default. Nonetheless, the past 40 years brought us a low-fat craze. Fresh food can still taste good without a higher fat content, but processing low-fat food makes it taste like crap. Companies understand this, and so they add a bunch of sugar (and often salt) to fix that problem. This process essentially exchanges fat your body can actually use for fructose-produced fat that it cannot.

These are the main reasons why processed food is often an enemy if you want to stay healthy. This isn’t always the case, but it is far more likely than not. Check the sugar content on the back of every package of processed food you own or see at the supermarket and you’ll see it for yourself.

Healthier Sugar Consumption

OK, so some sugar isn’t really bad for you but some sugar, like fructose in high amounts, is unhealthy. Since fructose is plentiful in many processed foods, how can you eat better and still enjoy the sweet things you like? What follows are some suggestions. Some require a bit of sacrifice and will be difficult — but more effective — and others are easy enough for anyone to incorporate in his or her diet. If you want to try and curb your sugar intake, be reasonable about what you can accomplish. Failure is a lot more likely if you try to pack in large amounts of change at once . When you cut back on anything slowly, it feels much easier and is more likely to stick.

Stop Drinking Sugared Beverages

All of that is bad, but what makes it so important to stop drinkingsoft drinks is that you get absolutely nothing else with it. While other sugary items — such as a slice of cake or a doughnut — are no shining examples of nutrition, they at least contain some nutrients that will help to alert your brain that you’re actually eating. Fructose-heavy soft drink won’t do this, so it’s best to just cut it out entirely. This is the hardest thing but the most important. Cutting it out will make it easier to stop eating too much sugar (or anything, really), because you’ll be taking in far fewer calories that will go unnoticed by your brain.

What can you drink without issue? Water.

This may sound horrible to some people, but pretty much every other drink you can buy is a processed drink. This isn’t to say you can never have another sugared beverage again, but the more you drink them the harder it will be to control your appetite. If you want to incorporate sugared drinks and alcoholic beverages into your diet, try consuming them 20 minutes after you’ve eaten. You can use this same trick for desserts. (More on this in a minute.)

Eat Fibre with Your Sugar

So how do you eat fibre with your fructose? Don’t eat processed foods. Get your fructose from fruit or other sources that contain built-in fibre.

Avoid Processed Foods with High Amounts of Sugar

actually whole wheat

Keep Sugar Products Out of the House

Don’t Cut It Out Entirely

Photo by Nick Depree

If you’re currently eating quite a bit of sugar, or you really like it, cutting it out entirely is a bad idea. Not only is comfort food possibly good for your mental health, but it’s also believed that you can develop a dependency to sweet foods. As an experiment I cut out sugar for a month before writing this post. While the physical cravings were easy to curb, the psychological ones were much more challenging. Angela Pirisi, writing for Psychology Today, points to a study conducted by psychologist Dr Bart Hoebel, who believes sugar creates an actual dependency:

Laboratory experiments with rats showed that signs of sugar dependence developed over the course of 10 days. This suggests that it does not take long before the starve-binge behaviour catches up with animals, making them dependent. There is something about this combination of heightened opioid and dopamine responses in the brain that leads to dependency. Without these neurotransmitters, the animal begins to feel anxious and wants to eat sweet food again.

Artificial sweeteners didn’t change the dependence, leading Hoebel to believe that the sweetness was the main factor and not the calories. While the study couldn’t identify why these cravings exist, it could identify a dependency. If you’re cutting down on sugar, take it slowly.

Get Moving

sitting the harbinger of deathWe’re big on standing deskshelps your burn far more calories than sitting

Like with anything, sugar isn’t all that bad for you in moderation. The problem with sugar these days is that there’s a lot more of it in everything and it’s in practically everything. So long as you pay attention to what you’re eating and you don’t overdo it, sugar can be a pleasant part of your life few to no issues. The important thing is that you know what you’re consuming and make good choices as a result. The answer to this problem isn’t groundbreaking, but just a matter of paying attention.

Want to learn more about sugar and how it works? You’ll find a lot of links within this post to other studies and additional information that’s worth reading, but you also should check out Dr Robert H. Lustig’s lecture on sugar (which was the initial reason for writing this), as well as Sweet Surprise, which is an HFCS advocacy website that argues against the claims that it is bad for you.


  • We Created the Fast Food Monster

    It’s our fault it has grown to extreme proportions and even if tomorrow everyone in the world stopped supporting them, they have enough power & of our money to dominate the market for decades.
    They’ll change when their fast food chains aren’t making them yachts every second to abusing the supermarket (which they already do).

    Every time you buy fast food, that’s one vote for an obese society where food is the

    number one killer

    In the west.

    Listen to this article & myself, let us help you, help us, help the world!

    • REALLY good info here. For even easier understanding, it’d be great if we could all report in the standard (Australian) metric energy units of kilojoules, rather than these American (old imperial) unit of ‘calories’; kJ are clear enough, but we’re being polluted by ‘calories’ with our slavish adoption of US stories and articles verbatim, instead of a little local research and conversion as required.

  • Nice article, Adam. Possibly useful in your section on soft drinks to also point out that fruit juices are not that great for you either, due to the fact that you’re getting the fructose without the majority of the fibre – essentially just another sugar hit.

    Anyone interested in looking into this more deeply, or food-based health in general, should check out Mark Sisson’s blog at marksdailyapple.com. There’s some really excellent – and inspiring – information there for those ready/willing to break the fast-food/processed-food habit. There are also a couple of excellent cookbooks available to help with recipe ideas and recipes submitted by readers (which are free!).

    To your health!

  • Hi, great post. We have all given up sugar in our house. My husband “needed” to have something sweet everyday and whilst none of us are over weight, his moods would change depending on his sugar intake. My youngest daugther and I have also been suffering from a Candida skin infection and within 3 days of cutting out sugar and caffine we were improved. Thanks again, I am posting this link to my blog.

  • I’m a recent sugar quitter. i read a scary article by a resarcher linking sucrose and fructose to cancer triggers pointing to the sky rocketing cancer rates in the US while in, say, France, they eat tons of fatty food and heaps of alcohol (and smoke with impunity!) but have much lower rates of common cancers.

    I was very bad, tablespoons in my cereal, three in my coffee and tea, soft drinks and energy drinks all day and usually a candy bar. I didn’t eat a lot but what I did was almost always pure sucrose.

    It’s been really rough, horrid the first two weeks, but I can drink and enjoy coffee and tea without sugar now and have 3 bottles of water always chilled in the fridge (also screw bottled water, what a rip off, chilled tap water tastes the same). It’s funny how quickly your taste buds change and adapt.

    Honestly I thought I’d be miserable, which is why it took me years to get wise (32 currently). But I feel happier and healthier, I’m not as moody or depressed, I don’t get tired during the day and nod off watching TV. It’s great.

    Seriously, this is coming from someone who three months regularly had four weetbix every morning with four tablespoons of icing sugar on them. Quitting sugar is a good thing.

  • I’m tired of all the “stand up at work” stuff…
    Not because I don’t agree, I have a disability that prevents me from standing up for more than 20 to 30 minutes at a time without feeling quite fatigued. So now I have all these fears about not being upright enough and it shortening my life, what about people who are wheelchair bound, they’re pretty much screwed!

  • Thank you, this was a great post.
    I’d also recommend David Gillespie’s “Sweet Poison Quit Plan” as a really useful how-to guide for those of us wanting to give up our sugar addiction.
    And yes, I’ve fallen off the wagon a couple of times. It IS an addiction and it IS hard to give up.

  • Hey Dr boon a friend of mine is wheel chair bound and he plays wheel chair rugby sounds interestingly dangerous right? it still gives him exercise so think again dude your only “screwed” if you don’t do your research on what possible exercises that are available for you.
    As for junk food its another no brainer its all bad for us, try the palio diet if your overweight

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