Health: Sugar vs Fat: Which Is Worse For Our Health?

Sugar vs Fat: Which Is Worse For Our Health?

Weight-gain and health problems can be blamed on lots of things… Stress, Lack of Exercise and of course, Diet…

If we look at the latter, two bad boys which seem to pop up more than most are ‘Sugar‘ and ‘Fat‘.

People who opt for ‘Low Fat’ or ‘Low Sugar’ produce are usually not doing so because they prefer the taste (and even if they find out they do, that wasn’t the reason they started with).

They are doing so either because they want to lose weight, or they want a healthier diet, or both.

So which causes us to put on more weight, and which is worse for our health?

My Diet Experiments

So I love to experiment, that and setting myself lots of challenges (with most of the former including an element of the latter). So, when I read Tim Ferriss’ 4 Hour Body book about the ‘slow carb’ diet (I also love to read), despite having zero interest in diets prior to that point, I looked down at the middle-aged spread that I’d been starting to cultivate and felt that it would be a good thing to try out.

That was the start of my Slow Carb diet experiment.

The great thing about this was not so much the effect it had on my body, but more the amount I learned about health through following this experiment, including dispelling a few myths which had probably floated into my consciousness subliminally from years of media hype.

Hence began my interest with diets and health – at least much more interest than I’d ever had before. So I then wanted to find out more:

I should also say that I either never had the time or the enthusiasm to wade through all of the information and get to the truth. As health and diets weren’t top of my list of favorite discussion topics, the only thing that would interest me were interesting concepts (like the 4 hour body/slow carb theory which sparked my interest), answers or conclusions. Just give me the 5 minute version.

Luckily for you, these days you have articles like this one to tell you very briefly what all the (latest – it’s never finished) research has shown.


Our bodies extract sugar (in the form of glucose) from foods found naturally in our environment, but we’re not so well built to consume it in refined form.

Glucose is used as energy by all the cells in the body. Muscle cells consume glucose for muscle movement. We also need sugar in order for our brain to function well. The brain is the top consumer of glucose (20 to 25% of glucose consumption is made by the brain).

Note: On a low-carb diet, the process of ketosis produces the chemical ketones which can be used in place of sugar to fuel the brain – but as described below, this is actually really bad brain food and research has shown (via the experiment described below and elsewhere) that the results are a pretty significant dip in both mental and physical performance as well as potential health issues.

Refined sugar, as found in sweets, cakes and fizzy drinks passes readily and quickly into the bloodstream.

The sugar ‘Crash’

The sudden increase in blood glucose levels from food or drink rich in sugar is kept in check by insulin, a hormone secreted by the pancreas, but the rapid rise and fall of sugar levels in the blood cause a ‘crash’ about an hour afterward.

Longer term effects of too much sugar

Repeated surges in blood glucose levels and prolonged elevation of blood sugar puts undue stress on the pancreas and causes pancreatic cells to falter and eventually die, resulting in diminished insulin secretion – diabetes.

What happens to unused sugar in the bloodstream?

The liver and muscles store a limited amount in the form of glycogen, to be released when needed. The rest is stored in fat tissue as triglycerides.

Excessive fat storage leads to weight gain and obesity, which in turn causes many health problems, including heart disease and diabetes.

Why are natural sources of sugar better?

We’ve written plenty before about the wonders of the simple apple, so let’s use this as an example and if you like you can read more about apples in our article: Wonder-Food: The Apple – To be Eaten Raw, Unpeeled, Organic and Unbruised!.

An apple contains a lot of sugars in the form of carbohydrates, but these are bound to fiber and so it takes some time and use of energy before the digestive system can free and absorb the sugars, making for a much healthier consumption and one our bodies are far better designed for.

Artificial Sweeteners vs Sugar

Obviously one possible replacement for sugar is the artificial sweetener. Almost all low or zero sugar drinks use artificial sweeteners such as aspartame, a man-made, synthetic sweetener which is an excitant and is apparently very addictive (I don’t know enough about it to make an argument about that here and that’s not the point of this article) – a lot of people would argue that whilst the media and marketing tell you it’s low sugar and therefore ‘good’ – it is in fact far worse for you. According to this article there are 92 different health side effects associated with aspartame consumption: Aspartame Side Effects.

So perhaps the subject of another article one day but we’re not going to get into the debate over sugar vs artificial sweetener here, this one is about sugar vs fat.


Good fats are essential for body and basic brain functioning.

Some vitamins (namely A, D, E, and K) can only be digested, absorbed, and transported in conjunction with fats. Fats are also sources of essential fatty acids, an important dietary requirement.

Fats play a vital role in maintaining healthy skin and hair, insulating body organs against shock, maintaining body temperature, and promoting healthy cell function, as well as serving as energy stores for the body and offering protection from a number of diseases (the body can diminish the impact of harmful substances, protecting vital organs, by storing these in new fat tissue).

So it is nearly impossible to remove fat completely from the diet, and you wouldn’t want to do so because that would be unhealthy. Some fats are essential, others can be produced in the body by other compounds.

But then we have the ‘bad’ fats.

Saturated and trans fats can do significant damage to the body as highlighted in this article: Ban Trans-Fats From Your Shopping Bags! (basically attacking the immune system, causing inflammation and reducing levels of ‘good’ cholesterol to mention but a few of the bad effects).

Excess fat in the blood – good and bad – are eventually stored in fat tissue. As in the case of excess carbohydrate intake, this can lead to weight gain and obesity, along with resulting complications.

Sugar vs Fat

So, as we can see above, both are pretty bad for our health if taken in excessive quantities.

But which is worse?

For years ‘Fat’ has been seen as bad for you – it makes you, well, fat. In more recent years, though consumption of the right fats have been much more promoted and understood and there has been a move toward instead seeing carbohydrates as the most wicked of fattening ingredients (hence all of the low-carb diets out there).

In a recent experiment, two twins, Alexander and Chris Van Tulleken, followed a no-carb (essentially no sugar) and extremely low fat diet (as no fat at all would be impossible) for a month.

Both of these guys are doctors and conducted this experiment, including plenty of research and interviews with lots of scientists for BBC’s Horizon programme in the UK.

What I found interesting was that they are identical twins – extremely useful in experiments like this because they have exactly the same genes. So changes they observed are far more likely to be due to the diets and not genetics.

Some of their findings were pretty interesting:

  • both of the diets were miserable (I could have told you that from some of my experiences)
  • removing all carbs, Alexander suffered from constipation, felt slow and tired and had really bad breath (though didn’t feel hungry)
  • on the low-fat diet, Chris never felt full
  • on the low-carb diet, Alexander felt thick-headed and slow and lost considerably in a stock-trading simulation vs his brother (who in the simulation tripled Alexanders earnings over an hour period)
  • Alexander (low carb) lost more weight, but Chris (low fat) pretty much thrashed Alexander in every other test (strength, energy, thinking power,…)
  • tests to assess their levels of blood fats and risk of diabetes indicated that Alexander’s body had been fuelling itself in the absence of carbs by breaking down muscle tissue
  • their main finding was that fat vs sugar is the wrong question, as removal of either to the extent attempted in this experiment is dangerous for your health

You can read more about their experiment in this article: One twin gave up sugar, the other gave up fat.

Which is More Addictive?

This answer may surprise you:

Neither on its own is very addictive.

Think about it, you don’t eat sugar on its own. You may take it on your cereals, in your tea/coffee, or use it as an ingredient, but when was the last time you tucked into a nice bowl of sugar?

Similarly, you don’t eat raw fat, or anything even close. It’s just not very appetizing, which leads us to the logical conclusion of what IS addictive – and given we’ve had a heading with just about every other combination of the two words, I have to make it a new heading too…

Sugar AND Fat

Neither is particularly addictive, but when you combine sugar AND fat, then we’re in the realms of some pretty strong addiction. Some of the scientists interviewed in the programme mentioned above stated the following:

“…a combination of fat and sugar (such as in milk chocolate or ice-cream) has a similar effect on your brain to cocaine.”

Remove either fat or sugar from ice cream or chocolate and you’ll find, as mentioned above that it suddenly loses its appeal.

Excessive Diets vs Moderation

I told you I love to experiment, and part of that process naturally leads me to constantly question my own knowledge, choices and conclusions and to re-evaluate. Sometimes to ‘pivot’ – to change my approach on something based on the feedback I get.

One conclusion that I keep on re-confirming to myself… well, it’s not as strong as a conclusion… let me say that again.

One feeling that I keep re-confirming is that when we do anything really excessive, it’s not only harder to sustain, but it’s probably detrimental to our long term health. Moderation (if you can manage it) is definitely the way to go.

Perhaps all of these rules and systems are just ways for abstainers like me to find a way to get closer to moderation so that we don’t consume too much [insert offensive food/drink (s) here].

Final Thought

The overriding conclusion for me at the moment is in the form of a little light bulb with an associated ‘ding’ noise. It is something small but powerful enough to cause a slight adjustment to my thoughts and approach.

That thought is this: It’s the combination of fat and sugar that is dangerous.

Note: I replaced addictive with dangerous, but I think it’s a pretty safe extrapolation that if too much fat or too much sugar have been the bad guys for this long in research and in the media, and if I’ve been following a largely low-sugar based regime, a sensible adjustment to make would be to instead follow a largely (very low)-(sugar+fat) regime.

That’s what I’ll be trying next in any case!

P.S. If you want a really great and really brief basic guide to nutrition, Isabelle’s sheep article which I mentioned above is definitely worth a look!


Health: Sugar vs Fat: Which Is Worse For Our Health? — 4 Comments

  1. Very interesting points. You know I remember reading something about the addictiveness of sugar and fat. I don’t remember the specifics, but apparently just seeing ads of fatty and sugary foods releases dopamine in the brain giving you pleasure. I guess it happens when you eat that kind of stuff too. But the perverse thing is that the more of that stuff you eat, the more you need to eat to get that dopamine kick again. So I guess the trick is to avoid that stuff as much as possible so you don’t fall into a trap of eating more and more of it.

    • Do you mean you read an article or a book? Do you remember – I’d be interested, if it’s a book as I know you read some very good ones.

      Interesting point about the ads and now that you mention it, I recall some info along those lines, I think maybe it was in ‘Influence’ by Cialdini, but not sure.

      I’ve definitely also experienced the effect that the more you eat the more you want/need to eat to get the same kick. For me it was a realization that when fully on some of these diets, I didn’t miss the ‘treat’ foods – only just after cheat day on the slow carb diet for example.

      The thing I really wonder about is not the obviously ‘bad’ stuff such as cakes, candy etc but things like pasta which I would previously have classed as OK (at least not so bad) and bread, when eaten in a meal with meat/fat. e.g. how bad is a sandwich (which is also a combination of fat and sugar)?

      This has been very interesting for me because there really is usually talk about low fat or low sugar but it’s true we don’t usually consider the two together – seems obvious when you think about it but I have to admit it wasn’t for me…

    • Thanks Raquel, I’m glad you got something from this.

      I have certainly modified my thoughts and approach over the various little experiments and bits of research into the matter – this change is small, but I think quite fundamental.

      It’s not so much sugar, nor fat, but sugar+fat we have to be wary of.

      It still doesn’t make it black & white because lots of foods do still have these two ingredients to a greater or lesser extent but it gives us a new frame to look at the issue…

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