We talk with Johannes Lindenmeyer about addiction to sugar.DW-TV: Mr. Lindenmeyer, should we actually ban sugar, or maybe treat it like alcohol and not sell it to anyone under the age of 16? Johannes Lindenmeyer: No, we need sugar to live. But what is needed is a moderate consumption. We live in times when the food industry tries to increase our consumption of sugar, and this could be dangerous in many respects. Our teeth, diabetes ... And for some people, only a few but some, something like an addiction.   So there should be something written on the food saying: so and so much sugar is actually in it. That’s necessary for many reasons. It should definitely be the case, and the best way to have it simple is like traffic lights. You have the green, yellow and red dots. But that's what the food industry does not want. Are there similarities between the different addictions? Whether you compare sugar or something like alcohol. There's something like a final pathway with all addictions, and that's the permanent changes in the reward system. But the addictive potential of substances is different. There are highly addictive substances like heroin or nicotine, and sugar is more at the low level. But it's more or less just a gradual difference. The fundamental similarity is in the brain. You could say so - although for having a high addiction potential you need a two-phase effect. And this two-phase effect in the case of alcohol is much stronger than for sugar. And what does two phases mean? That you have an immediate rewarding effect, and afterwards you have a negative effect. It's long as strong as the positive one, but it lasts longer. So that increases of probability of you repeating the consumption. And when we eat sugar at a birthday party we will not have a hangover. Exactly. I eat chocolate because I sometimes just love to, but I can always stop - most of the time. Why are there people who can't stop? That's somet...