The harmful effects of sugar go way beyond empty calories.
Added sugar is so unhealthy that it is probably the single worst ingredient in the modern diet.
Here are the top 9 reasons to avoid sugar as if your life depended on it (it does).
1. Added Sugar Supplies a Large Amount of Fructose
The reason added sugar (and its evil twin… High Fructose Corn Syrup) is bad for you, is that it supplies a very large amount of fructose.
Sugar (and HFCS) are half glucose, half fructose. Glucose is essential and can be metabolized by pretty much every cell in the body. If we don’t get it from the diet, our bodies make it from proteins and fat.
Fructose, however, is not essential to our functioning in any way.
The only organ that can metabolize fructose is the liver, because only the liver has a transporter for it (1).
When large amounts of fructose enter the liver and it is already full of glycogen, most of the fructose gets turned into fat (2).
This process is probably one of the leading causes of the epidemics of many chronic, Western diseases.
I’d like to point out that this does NOT apply to fruit, which are a real food with vitamins, minerals, fiber, lots of water and are very difficult to overeat on.
Bottom Line: The only organ that can metabolize fructose is the liver. When we eat a lot of fructose, many things in the body start to go wrong.
2. Sugar Doesn’t Contain Any Vitamins or Minerals (Empty Calories)
Sugar IS empty calories. No doubt about that.
Most high-sugar foods like pastries, sodas and candy bars contain very little essential nutrients.
People who eat them instead of other more nutritious foods will probably become deficient in many important nutrients.
Bottom Line: Most products with added sugars in them contain very little nutrients and can therefore be classified as “empty” calories.
3. Sugar Causes Deposition of Fat in The Liver
When we eat fructose, it goes to the liver.
If liver glycogen is low, such as after a run, the fructose will be used to replenish it (3).
However, most people aren’t consuming fructose after a long workout and their livers are already full of glycogen.
When this happens, the liver turns the fructose into fat (2).
Some of the fat gets shipped out, but part of it remains in the liver. The fat can build up over time and ultimately lead to Non-Alcoholic Fatty Liver Disease (4, 5, 6).
Bottom Line: Eating a lot of added sugar (fructose) can cause deposition of fat in the liver and lead to Non-Alcoholic Fatty Liver Disease.
4. Sugar Harms Your Cholesterol and Triglycerides
Most of the fat generated in the liver gets shipped out as Very Low Density Lipoprotein (VLDL) particles.
These particles are rich in triglycerides and cholesterol.
In a controlled study, people were assigned to drink 25% of calories as either a glucose-sweetened drink or a fructose-sweetened drink for 10 weeks (7).
The fructose group had:
- Increases in blood triglycerides.
- Increases in small, dense LDL and oxidized LDL (very, very bad).
- Higher fasting glucose and insulin.
- Decreased insulin sensitivity.
- Increased fat in the abdominal cavity (visceral fat).
Basically, 25% of calories as fructose significantly harmed blood lipids and caused features characteristic of the metabolic syndrome, which is a stepping stone towards obesity, heart disease, diabetes and a (short) lifetime of poor health.
Bottom Line: Consuming a large part of calories as fructose can lead to serious adverse effects on blood markers in as little as 10 weeks.
5. Sugar Causes Insulin Resistance
The main function of insulin is to drive glucose from the bloodstream into cells.
But when we eat a Western diet, the cells tend to become resistant to the effects of insulin.
When this happens, the pancreas start secreting even more insulin to remove the glucose from the bloodstream, because elevated blood glucose is toxic.
This is how insulin resistance leads to elevated insulin levels in the blood.
But insulin also has another important function… it tells the fat cells to pick up fat from the bloodstream and to hold on to the fat that they already carry.
This is how insulin causes obesity.
When the body becomes even more resistant to insulin, the beta cells in the pancreas eventually become damaged and lose the ability to produce sufficient insulin. This is how you get type II diabetes, which now afflicts about 300 million people worldwide.
Excess fructose is a known cause of insulin resistance and elevated insulin in the blood (8, 9, 10).
Bottom Line: Excess fructose consumption can lead to insulin resistance, a stepping stone towards obesity and diabetes.
6. Sugar Raises Your Risk of Western Diseases
Excess sugar consumption has been associated with many Western diseases.
If anything, sugar is the single largest contributing factor to the poor health of affluent nations.
Every time sugar (and refined flour and vegetable oils) enter a population’s diet, these people become sick.
Sugar has been associated with:
- Obesity. Sugar causes weight gain via various mechanisms, including elevated insulin and leptin resistance (11, 12).
- Diabetes. Sugar is probably a leading cause of diabetes (13, 14, 15).
- Heart disease. Sugar raises the bad cholesterol, triglycerides and causes various other issues that can ultimately lead to heart disease (16, 17).
Bottom Line: Excess sugar consumption has been associated with many serious diseases, including obesity, type II diabetes and cardiovascular disease.
7. Sugar Doesn’t Cause Proper Satiety
An area in the brain called the Hypothalamus is supposed to regulate our food intake.
In a study published in 2013, two groups drank either a glucose-sweetened drink or a fructose-sweetened drink (18).
The glucose drinkers had decreased blood flow in the hypothalamus and felt satiated, while the fructose drinkers had increased blood flow in this area of the brain.
The fructose drinkers felt less satisfied and were still hungry.
Another study revealed that fructose didn’t reduce levels of the hunger hormone ghrelin like glucose. The more ghrelin, the hungrier you are (19).
Bottom Line: Studies comparing fructose and glucose show that fructose does not induce satiety like glucose, which will contribute to a higher calorie intake.
8. Sugar is Addictive
When we eat sugar, dopamine is released in the brain, giving us a feeling of pleasure.
This is actually how drugs of abuse like cocaine function (20).
Our brain is hardwired to seek out activities that release dopamine. Activities that release an enormous amount of it are especially desirable.
In certain individuals with a certain predisposition to addiction, this causes reward-seeking behavior typical of addiction to abusive drugs.
Studies in rats demonstrate that they can in fact become physically addicted to sugar (21).
This is harder to prove in humans, but many people consume sugar and other junk foods in a pattern that is typical for addictive, abusive compounds.
Bottom Line: Sugar, due to its powerful effects on the reward system in the brain, can lead to classic signs of addiction.
9. Sugar Causes Resistance to a Hormone Called Leptin
Leptin is a hormone that is secreted by our fat cells. The more fat we have, the more leptin is secreted.
This is supposed to function as a signal to tell the brain that we’re full and need to stop eating. It is also supposed to raise our energy expenditure.
Obese individuals actually have high levels of leptin, but the problem is that the leptin isn’t working.
This is called leptin resistance and is a major reason why people eat more calories than they burn and become obese.
Fructose is a known cause of leptin resistance, both because insulin blocks leptin signalling in the brain and because fructose raises blood triglycerides which also blocks the effects of leptin (22, 23, 24).
This makes our brain think that the fat cells are empty and that it needs to keep eating.
Willpower is very weak compared to the leptin-driven starvation signal.
This is the reason people can’t just “eat less, move more” and live happily ever after.
To reverse leptin resistance and make the brain WANT to eat less, sugar has to go.
I have been completely off sugar for over 6 months now, and this is the first winter that I have not gotten sick more than my husband! Usually it is the opposite! So I am a believer. Only two minor colds for me in 6 months, none that had me down for the count. Instead, my husband who is normally healthy just because he has a stronger constitution than I, well, he has been sick for 6 weeks now!
Interesting read about sugar is an older book called “Sugar blues” I believe the author is Dufty. It explains how if sugar was discovered today it would be as illegal as heroin…..
I read the Sugar Blues in 1979 – it is excellent and pertinent today.
Interesting article! However I think you’re comparing a sugar (fructose) with a sugar (glucose) in a lot of instances which, can get confusing for people who don’t have a primer in the matter of the different types of sugars.
All in all though, very informative. Thanks.
In the 80′s it was salt, then it was fat, then cholesterol, now sugar is the devil. Hopefully we’ve arrived at the right one. I, for one, think sugar is the basis of a lot of health problems and eating less sugar seems to only be a huge health benefit.
Good article but I think you’re incorrect when you say that it does not apply to fruit. Fructose is fructose. And I think it’s very easy to overeat fruit, especially in the form of smoothies etc.
Fructose for many should be zero in ANY Form… Until they are lean machines…etc…for a year…. then Once a week… One serving…
and never ever…. in liquid form!!!
Yes…. I agree…. Fructose….is and should be ZERO!!!
I too have been off sugar since September 2011 and this is the first winter in decades that I didn’t get sick once. I’m usually good for one bad upper respiratory infection. Yet despite all of my coworkers being sick at one time or another I haven’t been sick once.
Just be sure to clarify that it isn’t just added sugar that causes the above-named health problems. All carbohydrates metabolize as sugar and that sugar can be every bit as damaging, especially to those who are insulin-resistant genetically or from bombarding their bodies with sugar for years. And fructose is fructose – even if it comes from a piece of fruit. The body can’t tell the differences, so fruit is not an “eat all you want” food.
Fructose does not raise insulin levels like glucose does.
Sugar gave me cancer and killed my parents. :(
Your articles are so interesting and I read everything on your blog! It’s great but the pictures drive me crazy! I have a weakness for chocolate so seeing pictures of people eating it makes me crave it so much! (It’s also annoying how slim and good looking the people in the pictures are, extremely unrealistic if that were their diet). Ah well I guess I better get used to resisting temptation. Thanks for the info! :)
Holly, you can eat a piece of 85% or higher cocoa sometimes. I have a small square of it every day w/ a teaspoon of peanut butter. I like a glass of milk or cup of coffee with it. Yes, it is an “acquired taste.” The good news is, no one in the household is going to steel your chocolate!! Check out the label, a small square has about 4 carbs in it. It is just right, because a larger piece gets to be too much… except on special days…
Hi Kris! Nice and informative article. Just wanted to ask one question related to your previous article on how keeping away from wheat and sugar you have lost so much weight. Please let me know if by wheat you mean the refined flour or the unrefined variety too.
I mean both refined and whole wheat. I also avoid spelt and other gluten grains.
Great article! It’s always so funny to me how people are so anti-fruit because of “all the sugar.” As mentioned in the article, whole fruits are full of nutrients and vitamins… and eating whole fruit is NOT the same as having a smoothie. Smoothies are usually chalked full of other crap- they’re not just fruit. As someone in the medical profession, I can say with confidence if you gave up eating all refined sugar, but continued to eat fruit, you’d still be healthier than 99% of America. As a vegetarian, I can tell you that it’s definitely hard to over-eat fruit… and if I did, so what? My BMI and cholesterol are really low. Whole fruit found in nature is absolutely good for you.
G,
You are so right Whole Fruit is so good for us.
YET There are many who have hidden inflammation to all that sugar. They eat 3 to 8 servings a day and wonder why they can’t lose the 10 to 100 pounds. I have seen it over and over again… Cut out the Fruit… and when the body resets… after a year… then reintroduce but carefully. I am CONVINCED that Fruit the way I had it as a boy in SEASON and or ONCE a week or so is better than 2 to 5 apples/servings a day. I have watched my life on 3 to 5 bananas and watermelon(I love watermelon) etc… drop to ZERO and Weight and Health markers improve JUST as IF I gave up sugar!!! and BMI means nothing… Let’s hear your % of body fat….
You’re partially right. There’s so much fibre in fruit, that it’s hard to overeat it. But there’s not ‘so much goodness’ in fruit that you need it. Not eating fruit, but being on a western diet, will result in no deficiency. Eating fruit increases the number of vitamins in your pee, and not by very much.
Probably the correct statement is ‘one or two pieces of fruit a day will not harm you, but won’t really help you either, but you should never eat dried fruit, or drink fruit juice, in any form, because the sugar is concentrated and you will eat too much’. But, ‘don’t eat fruit’ is a simpler message that is easier to understand and does no harm, I think that’s why some people say that, instead.
Not eating fruit and eating a western diet WILL result in a deficiency of vitamin C. Fruit contains everything needed by the human body, including water. If people ate more fruit, they wouldn’t have to worry about getting their “8 glasses of water” every day.
G, I agree 100%. I wonder why people think nature created fruits and berries, and made them so flavorful to our palate. Funny how some people think we’re NOT supposed to eat delicious natural things that make us salivate, but they think we’re supposed to eat grains or furry, stinky animals.
So if I must use a little something in my oatmeal, what is my best option?
Your best option is to use water only with oatmeal. Oatmeal is not a healthy food anyway it stick to your gut wall and causes so many issues. Virtually impossible to get gluten free oats as well.
Gloria,
3 choices come to mind…actually 10…
1. 100 calories of coconut oil, butter, olive oil or ground up flaxseed… that last one is amazing..
2. Strawberries, blueberries…
3. If U really want to go out on a limb… Make it… runny… drink half… then at work for lunch drink the other half… Try Munch pause Munch… extend your overnight fast an hour or two…then add another… etc…and watch your body take off…. I rode 55 miles this afternoon and at the end… I was 25 hours without food… I ate rice, lentils, Chocolate whey in a puree with spices….YUM….then… 6 eggs, potatoes, butter, onions, cottage cheese, avocado, whole milk, then for desert I had a carrot dipped in peanut butter.
Never knew I could Not be hungry…and have this much energy… It truly works for an ever increasing number…and it is so flexible… 12 hours… to 48 hours… I love being full rather than having several meals that total 1500 to 4000 calories…depending on my caloric burn for the day… and I ingested all the sugar I needed without any Fructose…
Many demonize all kinds of foods.
Potatoes, white rice, lentils, are so much like sugar….NOT!!! They sure work for me. Of course no added sugar as in ZERO with Zero cheat days helps. Ok, maybe 2 or 3 times a year.
Except for the fact that our body’s cells need sugar to survive. Sugar provides energy for cells to function properly. Without sugar, we’d all die… yes, even us Type 1 Diabetics. Now, should you go out and chug a liter of Pepsi every day? Of course not. But to say you should “avoid sugar as if your life depended on it” is absolutely ludicrous.
It is pretty clear that the article is about added sugar (sucrose) and high fructose corn syrup.
Our bodies need glucose (we can produce it if we don’t get it from the diet), but no one needs fructose.
JD Greer,
ABSOLUTELY…Ludicrous???? Tell that to 339 million type 2 diabetics and a billion ? overweight and obese suffering people with all manner of diseases that would virtually disappear with Zero sugar and Zero processed foods. They are sick and dying and the cure is simple. There is amazing power in NONE !!! Just because they make it…(THE WHITE POISON) and we are conditioned to INGEST it doesn’t mean we can’t do away with it….and the benefit??? It is beyond words. Almost as Ludicrous as the countless doctors who smoked when I was a boy… Where are they now?
Refined Sugar in all its forms…. is simply and clearly a disaster… IT makes the Holocaust Look like a walk in the park. The fact that many can eat some… just shows… how calloused we HAVE become to the plight of those who like the alcoholic… MUST… find NONE to be the magic… glorious life saving pill.
Hyperbole much?
JD Greer, what planet do you practice medicine on? There isn’t one healthful thing one can say about sugar with the exception of its rocket fuel ability. When was the last time you needed to run from a predator? We carry 1 teaspoon of glucose in our bloodstream. Any glucose our “few” cells that rely on it, retina, red blood cells, our liver can produce through gluconeogenesis. Burning ketones is the healthiest fuel for your body. Your health is determined by one equation… “the proportion of fat versus sugar you burn in your lifetime. The more fat you burn, the healthier you will be. The more sugar you burn, the less healthy you will be.” Dr. Ron Rosedale.
Everyone gets confused by this. Lactose is fine. Glucose is fine. Fructose is the issue. The article came close to making this clear, but kept saying ‘avoid sugar’, which is an over simplification.
Thanks for the clarification Kris! I will try and remove all wheat and sugar from my diet and benefit from it.
There’s a book by an Australian called David Gillespie, called ‘Sweet Poison’. It’s full of details of studies and so on, very up to date. I read it, stopped eating fructose, and lost 20 kg in 6 weeks, without ever being hungry. I eat far more fat than I ever did, and have kept that weight off (again without ever being hungry, I eat whenever I feel like it ,and whatever I like, just no fructose), for over a year now.
Avoiding sugar (excess or otherwise) becomes even more paramount in menopause–your body will grab onto any little manufactured fat cell (of any type) and store it. A keto diet with very low carb (I’m talking Atkins Induction-style carb levels) is recommended to avoid a ballooning waistline that won’t be tamed.
i think i am lucky as i do not have a sweet tooth. So my sugar consumption was always low. But I was still overweight. Cutting gluten from my diet and doing strength training brought me to my ideal weight. Gluten was constipating me. No more suffering from constipation and bloating for me!
I have a slightly different view to what one should eat. Nature is the best recommendation and one should eat whatever your body feels like eating, if you feel like a sweet eat it, just remember everything is OK in moderation, overdoing the good things are also harmful. I am 72 years old and weigh 82Kg, have never gone to a gym and the most stressful exercise done was Big Game Fishing.
I am a chocaholic and consume lots of sweets mostly Dark Chocolate (85% Cocoa) and plenty of dried fruit, I eat a large bowl of fresh fruit every morning for breakfast and dring’k at least a litre of fresh fruit juice per day, mainly freshly squeezed orange juice, drink several cups of coffee with two heaped teaspoons of sugar daily, use only full cream milk and normal salted butter – no low-fat or margarine products.
During my later working career I had a record of 9 years without a single days sick leave. I have about one glass of wine a month and did smoke from the age of 21 till 40 then stopped completely, Maybe you will say I am an exception to the rule but I have several friends and family that follow a similar trend and lead healthy lives.
My mother lived till 98 and loved red meat and plenty butter on her food and bread, did not like vegetables but loved potatoes and ate lots of fruit. The only time that I had some health issues was in my fifties when I cut down on sweets, butter and used sweetener instead of sugar to try to lose some weight on my belly, needless to say it did not work, lots of fruit instead of starches and bread did the trick.
My Motto: Eat what your body wants when it wants it and everything in moderation, do not eat anything just for the sake of eating or because it’s meal time.
I agree. And I also think it’s not so much what we DO eat that leads to health problems but more likely what we DON’T eat.