Why Does Sugar Make People Fat?

Sugar in a wooden bowl

One of the most intuitive facts in nutrition is that eating lots of sugar makes you fat. I don’t really think that there is all that much disagreement on this point. There is certainly some argument about why this is true. The calories people claim that this is because it is a source of empty calories. So, therefore, you could eat sugar and skip dinner and not gain weight. HOT-Fatty-Liver2.1 copy

These people believe that eating a plate of brownies with some multivitamins and an equal calorie portion of kale salad with salmon is equally fattening. That’s not likely to be true, as common sense would tell you.

The calories people claim that since sugar is empty calories, you will then eat more food with nutrition, as if it’s really, really hard to avoid eating nutrient dense foods like liver, calf brains and kale. Hold me back… Can’t resist… The stewed calf brain…

Fructose is more fattening than glucose

I argue that the fructose is far worse than glucose because it causes fatty liver directly and therefore insulin resistance. This feeds into the vicious cycle of hyperinsulinemia and insulin resistance. I believe that it is the insulin resistance cycle that sets the ‘Body Set Weight’ and to successfully lose weight in the long term, you must address this cycle.

Both glucose (starches) and fructose play a role, but enter the cycle at a different point. If you eat massive amounts of carbohydrates in the form of glucose, it is still possible that you do not develop this vicious cycle if you do not have any fructose. As an example, the Chinese diet of the 1990s was extremely high in white rice (a refined carbohydrate and with lots and lots of glucose) but almost no fructose. They were also not eating 32 meals spaced throughout the day, so they weren’t keeping insulin levels high.

Intermap1Under this circumstance, there was very little obesity and even less type 2 diabetes. As the diet began to Westernize, and sugar consumption increases, this is simply a recipe for disaster and China has now passed the US in diabetes prevalence.

Since sucrose (table sugar) contains both glucose and fructose, it is especially dangerous. Fructose can only be metabolized by the liver, so 1 pound of sugar has 1/2 pound of both glucose and fructose. The entire body uses the glucose, but only the 5 pounds of liver needs to metabolize the same amount of fructose. Furthermore, the fructose will not be metabolized to glucose in the liver, because the body has just taken in a bunch of glucose. The body does not need any more glucose. Instead, the body will get busy turning that fructose into fat through de novo lipogenesis. Hey presto – fatty liver. Hey presto – insulin resistance. Hey presto – increased body set weight. Hello, diabesity.

Fructose-consumption4So, I believe that fructose is something like 20 times more fattening than glucose (starches), as we discussed last week.

So it is not really true when somebody says that eating a bowl of rice is the same as eating a bowl of sugar. A bowl of sugar is more like eating 20 bowls of rice. That is why fructose, specifically, is so, so fattening. That is really why reducing sugar is the most important step in reducing obesity. That is why those true calorie believers are so dangerously ignorant when they say that sugar is no worse than any other calorie. This, of course is the point behind Gary Taube’s excellent new book ‘The Case against Sugar‘.

The sources of fructose

guyenetSugar-768×498So what are the top sources of fructose in the diet? Beverages is the top source of sugar and should obviously be reduced. But the issue is whole fruit. It makes up a sizeable 18% of dietary intake. Should we reduce it? I confess that I do not have a good answer here. Biochemically, there is no difference between fructose in fruit and fructose in sugar.

However, there are an number of mitigating factors in whole fruit, including fibre. Is it enough? There is no good answer. Epidemiologic evidence does NOT link whole fruit consumption to obesity or diabetes, but that is not quite enough for me to give it a free pass.

Without adequate data, the best answer I can give is this. If whole fruit is the worst that you do in your diet, that’s OK. However, if you need to reduce weight, then consider reducing fruit. Yeah, I know, not a very good answer.

In response to Gary Taube’s book, there have been some who have responded that dietary consumption of sugar peaked and yet obesity continues to go up. This is considered ‘proof’ by some that sugar does not play a large role in the cause of obesity.

At first glance, this may appear to be true, and is certainly persuasive. However, a closer look reveals the truth.

Smoking as an analogy

guyenetCig3Let’s look at an analogous case of why smoking doesn’t cause cancer. The relationship between cigarettes and lung cancer. Here’s the graph of cigarette smoking and lung cancer.

Well this first graph shows that smoking ‘obviously’ was not a major cause of lung cancer, right? As the number of cigarettes goes down, lung cancer deaths continue to rise. All those anti-smoking people should be ashamed of themselves for all that fear mongering. Jeez.guyenetCig2

Well, let’s fast forward a few years. Here’s the full graph. There’s simply a time lag between smoking and lung cancer. That’s life. What you can see, when you look closer at the first graph is that the rate of rise of lung cancer death starts to slow as cigarette consumption drops. That’s the first step.

The same is true in sugar. Obesity is a multifactorial disease. Certainly sugar is one of the biggest factors, but not the only one. Reducing sugar doesn’t mean that consumption will go down right away, and the effects may need years or decades to show a difference. That does NOT mean that the hypothesis that sugar is a causal factor is incorrect.

Let’s look a bit closer at the data. I’ve put up the graph of obesity from the OECD and the USA data is highlighted in red.
OECD2014-2You can see that after the year 2000 there are two lines. The bolded line shows the actual incidence of obesity. The dotted line shows the past projection of obesity. In other words, the data clearly show that the rate or rise of obesity has clearly slowed.

Obesity was rising at a fast rate from 1977 to 2000. There is a momentous inflection point right at the year 2000. Obesity slows. Why? What happened? The Y2K bug? No. Sugar consumption peaked and then fell. The growth of obesity slows down.

Jason Fung


How to Lose Weight

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Earlier with Dr. Jason Fung

Fructose and Fatty Liver – Why Sugar is a Toxin

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Obesity – Solving the Two-Compartment Problem

Why Fasting Is More Effective Than Calorie Counting

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More with Dr. Fung

Dr. Fung has his own blog at intensivedietarymanagement.com. He is also active on Twitter.

His book The Obesity Code is available on Amazon.

The Obesity Code

His new book, The Complete Guide to Fasting is also available on Amazon.


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“It Was Amazing and the Weight Just Started to Drop”


Before and after

The amazing low-carb success stories on Twitter keep coming – and here’s another one.

If you want to know what Landon did to drop a lot of weight and feeling great without going constantly hungry, keep reading. He was kind enough to send us an email with more details.

The Email

So lets start out by stating that having a wife who is a research scientist comes in handy. She taught me how to find research documents and journals, how to read them, what to look for (funding, conflicts of interest, etc.) and told me that if you want to know the TRUTH… You start there; and so I did.

I ate spinach salads and some meat with TONS of blue cheese dressing (I eat it on almost everything!). When I returned, I had lost like 45 lbs (20 kg)

My name is Landon Veitch. I am a 36-year old I.T. manager who lives in Millersburg, OR. After I left the U.S. Air Force in 2007 due to an injury, I found it hard to sustain exercise and just general life interest as I felt like my life had disappeared. From 2007 to 2012, I did absolutely NOTHING to better myself and just packed on the pounds. I then decided to go back overseas to Afghanistan as a civilian to serve my country again. While here, the food needless to say was less than stellar. I ate spinach salads and some meat with TONS of blue cheese dressing (I eat it on almost everything!). When I returned, I had lost like 45 lbs (20 kg) (roughly 300 lbs (136 kg) down to 255 lbs (116 kg)) in a little over 6 months. I felt great, confident, more energetic, etc… But then regular real life hit.

My wife was not happy, was a stay-at-home mom with our son, in a state she didn’t know anyone and was becoming unhappy with me as my mental state had changed and the weight was packing back on. So we moved back to Oregon and in January 2013, I decided to follow in the footsteps of Drew Manning (aka Fit2fat2Fit), who did what I wanted to do… Drop like 75 lbs (34 kg) in 6 months. I bought some home gym equipment and started. I gave myself the 6 month timeline as well and I dropped weight just like Drew (roughly 300 lbs (136 kg) again down to 251 lbs (114 kg)). I was happy this time, was back home and thought nothing could stop me. But then I started noticing I was hungry ALL THE TIME! I mean I could eat 3 cups of broccoli, 2 large chicken breasts and maybe some grapes and literally be hungry a few hours later. I always struggled with food my whole life as I used to eat a lot and all the time but was never ‘fat’ in the traditional sense. So what happened AGAIN? You got it! I put the weight right back on and then some. By this time life was even more hectic as I had my son, my daughter, selling my home, work transitioning, etc. and I got all the way up to 330 lbs (150 kg). The heaviest I had ever been. I had to almost buy 50 in pants… I freaked. I went to my PCP and got my full blood work-up:

  • Liver Enzymes (ALT and AST) were 4-6 times higher than normal (228)
  • BP – 160/92
  • TC/HDL – 6.2
  • TC – 220
  • HDL – 31
  • LDL – 171
  • Non-HDL – 160
  • TRG – 284

I was not in the normal ranges for any of the tests. I was pre-diabetic, fatty liver disease but no insulin issues. I told him I feel hungry all the time and we tried all the classic remedies of calorie restriction, changing what I’m eating to filling foods, eat timing, workout pre and post foods, etc. and nothing worked. One day he said since I like research I should look into leptin since my focus was always on insulin as I thought that was my issue. I didn’t know what it was, thought it was a drug like a statin or something. Found out through the wife it’s a signaling molecule. She explained the whole breakdown to me and I was jaw dropped. I couldn’t believe it… Could this finally be my answer? But how to I change my Leptin issue?

So I started researching and I found a video on youtube of Dr. Daniel Pompa. I then went to his site and listened to a podcast with Dr. Dominic D’Agostino. I followed his work which led me to you Dr. Eenfeldt. I was shocked to find you were a family physician whom looked into LCHF which I was always told was called ‘Atkins’ and was only good for a small period of time, bad for long run, we NEED carbs to function, fat is bad, etc. But you stated that there was research to back this LCHF so I went looking and thats when I found the ketogenic diet. I heard it from Drew Manning, Dr. Pompa, Dr. A’gostino and on other research documents as well however I had not looked into what it was exactly (thought it was a science term).

I was fresh, I was clear, I could think, I wasn’t tired, I wasn’t hungry, I didn’t crave anymore…

Then I found what I call my life changing moment. Low Carb USA. There are world renown physicians, researchers, teachers, dietitians etc. that live and swear by LCHF. So I said ‘Hell I have tried everything else, why not?’ So Oct 15, 2016, I started keto and boy it was so tasty but so hard because I love fruit and not having any was like a damn cigarette to me. I couldn’t help myself at times. I stayed strong, got through my mild keto flu which was only a day or 2 and then BAM! Like a ton of bricks hit me at about the 1 month mark. I was fresh, I was clear, I could think, I wasn’t tired, I wasn’t hungry, I didn’t crave anymore. I mean it was amazing and the weight just started to drop. 22 lbs (10 kg) the first month. Of course I knew this was only water weight but I was like ‘no way I can sustain this’. but I did. I lost another 20 lbs (9 kg) and then another 20 lbs (9 kg) and before I knew it, I was 4 months into Keto and 65 lbs (29 kg) down. The killer part of this was I didn’t even work out any. This was just my body working for itself for once instead of against it. I know I have to start working out and that is the plan otherwise I will taper off, make excuses and get off the Keto train but no way! I love this train for it has given me my life back. This is a lifestyle for me now. Not a diet and I share this with everyone I know and meet because if it can do this for me. Maybe it can do that for someone else.

My blood panels now:

  • Liver Enzymes (ALT and AST) – PERFECT (28)
  • BP – 120/80 (like a poster child)
  • TC/HDL – 2.8
  • TC – 125
  • HDL – 48
  • LDL – 56
  • Non-HDL – 83
  • TRG – 126

PERFECT ACROSS THE BOARD! But I am not stopping there, I plan to continue this train down to a respectable 210 lbs (95 kg) for my height which is considered to be an optimal weight for me and keeping my panels in amazing spots 🙂



Congratulations Landon – simply put an amazing story!

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Low Carb Breckenridge Available for Online Streaming


If you want to attend the Low Carb Breckenridge conference next week, but you won’t be in Colorado, fear not! You can sign up for online streaming of the conference featuring some of the top low-carb experts.

Check out the lineup of speakers and sign up for the online streaming here:

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The Mind Behind Mercola.com

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Why should you care about the light you’re exposed to? How much protein should you really eat? And can you go on a ketogenic diet indefinitely without encountering problems?

Dr. Joseph Mercola is the founder of the massive alternative medicine website Mercola.com, the “#1 Natural Health Website” in the world, that gets an astonishing 20 million visits every month. Ivor Cummins and our camera crew sat down with him to ask these questions – and got some interesting answers.

Note that many of Dr. Mercola’s views are very unorthodox and controversial – like his focus on light exposure. We do not endorse all his products or alternative theories (in fact, sometimes we struggle to even understand them). But there’s no doubt that Dr. Mercola is a highly interesting man with interesting ideas. Enjoy our interview.

You can watch part of the interview above (transcript). The full 34 minute interview is available (with captions and transcript) with a free trial or membership:

The Mind Behind Mercola.com – Dr. Joseph Mercola

Join free for a month to get instant access to this and hundreds of other low-carb TV videos. Plus Q&A with experts and our new low-carb meal planner service, etc.

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World Heart Federation President: Fat Is Protective, Carbs are Harmful!

Get ready for action, with this new attention-grabbing talk by the president of the World Heart Federation, Professor Salim Yusuf. Here are just a few of the controversial, but likely correct, quotes:

  • “Above 40% carb we see a steep increase in CHD risk. Fats are protective.”
  • “Contrary to common belief the current recommendation to reduce sataturated fat has no scientific basis.” (at 20:20)
  • “You must have heard of the book Big Fat Surprise by Nina Teicholz. She shook up the nutrition world. But she got it right.” (at 20:33)

Yusuf also gets into the mistaken war on salt, where a moderate amount of sodium (3-5 grams per day) may be optimal.

It’s an excellent talk, if you can stand the slight over-reliance on observational data at some points (it normally does not prove cause and effect). Still, highly recommended!

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