Debunking Sugar as a Dietary Demon

April 01 2015

Sugar and sugary foods have been bashed in the media, in books and articles on nutrition and in the bodybuilding/athletic world for some time. Now, sugar is being blamed as the root cause of all weight gain and excess body fat, to the extent that people are afraid to have a single cookie, lest it completely derail their weight loss goals.

Demonizing Sugar Has Made It Harder for Many People to Eat Healthfully

One of the really unfortunate things about this is that it’s led to a reliance on artificial sweeteners, which pose several well-documented health risks. A less dangerous, but still unnecessary side effect is that it’s caused a lot of people to become frustrated with or even chronically fail at eating a healthy, balanced diet because they think that an effective fat loss diet requires complete deprivation of any sweets.

Research Does Not Support the Need to Cut Sugar from the Diet

The fact is that research has shown that the overall pattern of eating and the broader spectrum of a person’s regular diet has a much bigger impact on fat loss and muscle building than does any single food, including sugar.

Most of us know that missing one workout doesn’t spell doom for our fitness and health goals, but many of us think that one slice of birthday cake will. So, we spend an awful lot of emotional energy fighting off cravings for sweets or trying to regain our commitment and motivation after a slip-up. Both of these can easily become self-defeating cycles, so it’s important to know what the credible research does and does not say about sugar in the diet.

The three biggest reasons that the media and nutritional gurus give for cutting sugar from the diet are that sugar causes weight gain, sugar causes metabolic syndrome or insulin resistance and that sugar is addicting. But let’s take a look at what the scientific community says about these arguments.

1.     Sugar causes weight/fat gain.

There are a number of studies out there that argue against this premise and all of them state the same thing: that it is the overall consumption of calories that decides whether fat is gained or lost, not the source of those calories. 

In a study published in the American Journal of Clinical Nutrition, researchers compared the results of a high-sugar/low calorie diet with a low-sugar/low calorie diet and found that there was no difference in weight or fat lost by the participants. 

A similar study done by Sievenpiper et al found that when calories from sugar replaced calories from other high-glycemic carbs like flour, there was no effect on fat loss or weight gain. In other words, a high sugar intake on top of an already high-carb/high-calorie diet caused weight gain, but a diet that included sugar instead of other carbs still allowed study subjects to lose weight.

2.     Sugar causes insulin resistance/metabolic syndrome.

This argument is illustrative of oversimplifying how the body reacts to sugar consumption. Yes, eating sugar does cause a spike in blood insulin levels, as the brain signals the release of insulin, which is the hormone responsible from transporting blood glucose to the liver to be turned into glycogen, then transporting that glycogen through cell walls to be used as fuel. 

However, sugar itself doesn’t cause insulin resistance or metabolic syndrome. Long-term consumption of excess sugar and other high-glycemic foods, coupled with a lack of exercise is what causes these serious health issues.

Numerous studies have shown that even regular consumption of sweet treats (such as having a cheat meal, a cheat day or even a daily snack of a small, sugary treat, do not cause insulin resistance, metabolic syndrome or even weight gain, as long as the caloric intake and nutrient balance of the diet as a whole are good.

3.      Sugar is addicting.

This is one of the more recent arguments against sugar, but it’s already been debunked by the research community. In studies done on both humans and rats, sugar has not been found to be any more addicting than fats or protein.

What gave rise to this thinking is the fact that a sugary food, taken on its own (such as a soda or a handful of candy), will cause a quick burst of energy, but then a subsequent “crash” about two hours later. Most people, reacting to that crash, will naturally reach for another high-sugar treat to get that initial energy burst once more. It’s not that a sugar addiction has caused them to do so, it’s that sugar and/or caffeine are the fastest “cures”.

Yes, this can lead to a very unhealthy cycle, but this isn’t due to addiction; it’s due to habit and the very human desire for a quick fix. 

We’re not by any means advocating a high-sugar diet. However, regularly scheduled sweet treats and a balanced diet and lifestyle are not mutually exclusive. In fact, including treats is very often the best way for people to stay committed to a healthy diet.

It’s far better to allow yourself the occasional sweet while eating healthfully 98% of the time (and keeping your sanity) than it is to continuously fall off the wagon and lose your motivation due to a diet that is too restrictive.



Piquet RU1, Fuhrer D, Falk S, Zysset S, von Cramon DY, Stumvoll M (2006) "The effects of insulin on the central nervous system--focus on appetite regulation. "Hormone and Metabolism Research 2006 Jul;38(7):442-6.

Sievenpiper JL1, de Souza RJ, Mirrahimi A, Yu ME, Carleton AJ, Beyene J, Chiavaroli L, Di Buono M, Jenkins AL, Leiter LA, Wolever TM, Kendall CW, Jenkins DJ (2012) "Effect of fructose on body weight in controlled feeding trials: a systematic review and meta-analysis." Annals of Internal Medicine. 2012 Feb 21;156(4):291-304

Surwit RS1, Feinglos MN, McCaskill CC, Clay SL, Babyak MA, Brownlow BS, Plaisted CS, Lin PH (1997) "Metabolic and behavioral effects of a high-sucrose diet during weight loss." American Journal of Clinical Nutrition. 1997 Apr;65(4):908-15.