If you're thinking about removing all sugar from your diet, some of the world's best nutritionists have a suggestion: before you go into full restriction mode, take a look at the traditional Japanese diet.

A Japanese-style of eating has been modeled for years because people from Japan live longer than anyone on the planet (life expectancies of women and men are both more than 80 years, with women living an impressive average of 87 years).

Their diet is mostly what you would expect: plants, fish, and vegetables. And, according to the results of a study published in The BMJ, people who follow such a diet have a 15% lower mortality rate. But, lost in their diet is one interesting fact: the Japanese still consume an average of 83 grams of sugar per day, which is a lot of sugar. 

All of it leads to one simple question: Is sugar really toxic? The answer is one that surprises many. 

Why We Fear Sugar

To understand the crackdown on sugar, you need to go back to the 1980s. At that time, scientists believed eating fat was going to kill you (it was identified as the reason for rising obesity rates). The response was a massive shift in the food industry to low-fat everything, which resulted in an over-reaction of substituting more sugar at the expense of less fat to make packaged foods taste better.

Naturally, the door swung the other way, obesity rates kept climbing, and carbs and sugar became the newly identified problem (while dietary fat began its path to redemption). Next thing you know, everything was low-carb and you saw the rise of diets like Atkins.

But, as sugar consumption decreased (use of sugar has gone down significantly in the last 20 years, after hitting a high in 1999), obesity rates continued to climb. 

Sometimes, truth really is stranger than fiction. In the last 50 years, the average person has added nearly 500 calories per day to their diet. And yet, sweeteners – such as sugar – only account for 10 percent of that increase

Not to mention, the “Blue Zones” – the areas where people live the longest in the world – consist of people who follow carb-heavy (up to 70-80%) diets. If carbs (and sugar) were really the issue, then these people would have a lower life expectancy.

While limiting sugar isn’t a bad thing and eating too much can have consequences (more on that soon), the association that sugar is toxic and causes all of these health problems just isn't accurate.

There are hundreds of studies that show if you put someone on a high-carbohydrate diet, they don’t gain weight or become diabetic. It doesn’t happen with animals or people.

But, people who eat a lot of refined foods (from any source) have poorer health outcomes. That's to say sugar is involved in obesity and disease, but science shows it's not the primary cause. It's just one of many factors.

Does Low-Sugar Cause Weight Loss?

So, what's going on? It's a bit of a bait-and-switch.

Decade after decade, a new hypothetical cause is identified as the root of all health problems. Maybe you’ve tried going gluten- or dairy-free; not because you have identified an allergy but because you heard that it was the reason you gained weight. If you have an allergen or sensitivity, removing those foods can make a difference.

For everyone else, removing those foods is just a matter of removing calories, which will always result in some weight loss (assuming you won’t replace it with something else).

And that's the problem: even when sugar decreases, total caloric consumption remains high. And that's because many refined foods make you desire more food. In the simplest sense, foods with certain properties have a higher reward value and they make you want to eat endlessly.

This is why one slice of pizza or one scoop of ice cream is rarely just one serving. It's easy for these foods to spiral and lead to you to eat too many calories, even if you find a way to keep sugar low. The goal is less about removing any one food and more about identifying the triggers that make you want to eat more.

That's why limiting "hyper-palatable foods," the things that trigger the reward center in your brain is an established way to prevent overeating. According to Stephan Guyenot, author of Hungry Brain, these foods include high-calorie options, the combination of fat, sugar, and salt, and especially glutamate, which is that umami flavor which is a part of cooked meats and other foods. 

So, Is Sugar Toxic?

Let's start with a simple answer: no, sugar is not toxic.

If you look at actual toxicity levels, it takes about a lot of sugar to be lethal. For a 180/pound man, it would take about 6 pounds of sugar to kill him. (To do your own math, the median lethal dose is 30g/kg.) Comparatively, a man of the same size would only need about .6 pounds of salt to be lethal, as in 1/10th of the amount.

And once you start digging into all of the sources of sugar, it becomes instantly clear why labeling sugar as “toxic” is so dangerous and misleading.

Exercises scientist Brad Schoenfeld explains:

“When looking for explanations to the obesity epidemic, primary culprits are the proliferation of fast food options and a continual reduction in physical activity. Inexpensive, highly palatable, supersized fast-food has led to overconsumption and the technological revolution has progressively led to fewer calories expended.”

As we mentioned earlier, sugar consumption has been on a downward spiral for a long period of time. If sugar really was the issue, we should be getting healthier because we are eating a lot less of it.

That’s not to say that sugar isn’t part of the problem, but it hints at just how much the sweet substance is misunderstood. In fact, the approach of “I must remove all sugar” might be part of your dietary struggles. 

If you feel better by removing sugar, then, by all means, you should feel empowered to do so. But, if you believe that you must eliminate all sugars to be healthy, lose fat, and feel better, then you’ve been badly deceived. 

The Sugar Rules

If you eat sugar – and lots of it – all the time, then you’re asking for an increased likelihood of everything from obesity to diabetes.

But, all sugar is not off-limits. A gram of sugar is just 4 calories. And 4 calories will not make you fat. If you were to grab a fun-size bag of M&Ms, you’d take down 10 grams of sugar. Or, in other words, you just ate 40 calories from sugar. That's not a big deal.

But, here’s how a small bag of M&Ms per day could send more weight gain your way.

Unlike other foods (think protein), sugar doesn't leave you fulfilled. In fact, it’s the opposite. Eating sugar oftentimes leaves you unsatisfied and craving more sugar.

That’s the real “danger” of sugar. It can be addictive, but not nearly as much as cocaine (no matter what some fear-tactics will suggest) or as the act of eating itself. Heck, years ago, scientists looked at the release of dopamine (a neurotransmitter that is released as a “reward” signal and makes you want more of something) for different acts.

Eating food, like a cheeseburger, causes an increase of dopamine of about 100 units. An orgasm, for comparison’s sake, led to an increase of about 200 units, which led certain scientists to joke that 2 cheeseburgers = 1 orgasm. The point is clear: eating is inherently addictive.

And added sugars – whether it’s table sugar, cane sugar, or organic agave – are all too easy to over-consume.

If you want a place to start, try to remove sugars in liquid form. You can drink seemingly endless calories from sugar and still feel hungry. And that's why soft drinks are more closely linked to the current obesity epidemic.

Sodas and colas are by far the main source of added sugar in the average American’s diet, accounting for 34.4% of the added sugar consumed by U.S. adults and children. In that respect, fruit juices aren’t any healthier, either.

The lesson: if you’re going to eat sugar, the real danger is in finding the “off” button to make sure things don’t spiral out of control.

If you’re looking for rough guidelines, here is how much added sugar you could add per day according to the American Heart Association:

  • Women: 100 calories/day (about six teaspoons, or 25 g);
  • Men: 150 calories/day (about nine teaspoons, or 36 g)

What does that mean? In dessert talk, that’s 1 full-sized Snickers or about 6 Oreo cookies. But keep in mind: Added sugar winds up in a lot of unexpected places, like soup and pizza.

Our rule of thumb: in any diet – no matter which one you find most effective for yourself – you can feel confident that if 90% of your daily choices are “healthy” (proteins, vegetables, fruits, and so forth), then you have 10% of your calories to enjoy however you want without much concern.