When I picked up my kids’ birthday cake this week, I felt a tinge of guilt that I’m sure many people will find familiar. Isn’t this thing loaded with sugar? The health and wellness space is filled with people pushing zero/no sugar diets, sometimes as a short-term detox, sometimes as a long-term way of life. Sugar has been vilified by popular influencers and US Health Secretary Robert F. Kennedy Jr., who called it “poison” last spring.When Kennedy talks about “sugar,” what he really means is added sugar: the refined brown and cane sugars or syrups that often end in “-cose” that are used to sweeten candy, packaged granola, and Coke. While added sugars are broadly linked to diabetes, inflammation and obesity, and cancer, Kennedy (among others) has pushed the anti-sugar narrative to an extreme: The new US dietary guidelines released last month state that children under the age of 10 should not eat any added sugar. (The previous guidelines limited the prohibition to kids 2 and under.) Adults are also advised that no added sugars are part of a healthy diet — but if we do consume them, we should limit our intake to no more than 10 milligrams per meal (about the amount in a tiny container of Greek yogurt).Under Kennedy’s vision, Halloween and birthdays would never be the same. But beyond losing those treasured traditions (and the other treats that make life delicious), an absolute prohibition isn’t really supported by science. Sugar is so ubiquitous that we could never realistically run an experiment of what happens if you eat zero sugar. Instead, what we know is that less sugar is better for you than more. “Sugar” isn’t all bad — and it’s not one thing. It’s more about which sugars you’re eating and how much you’re consuming. Let’s break it down.The two sugarsGenerally speaking, sugar falls into two categories: naturally occurring sugars in fruits or carbohydrates and the “added” sugars that are artificially inserted into foods to add flavor. The added sugar in your frappuccino or cinnamon rolls is not particularly good for you, especially in large and frequent doses. But the naturally occurring sugars in fruits or even whole-grain carbohydrates are not really worrisome. In fact, they can be part of the healthy diet that even Kennedy endorses.Sign up for the Good Medicine newsletterOur political wellness landscape has shifted: new leaders, shady science, contradictory advice, broken trust, and overwhelming systems. How is anyone supposed to make sense of it all? Vox’s senior correspondent Dylan Scott has been on the health beat for a long time, and every week, he’ll wade into sticky debates, answer fair questions, and contextualize what’s happening in American health care policy. Sign up here.There is a physiological reason to make a distinction between the two types. Sugar in your fruit is combined with other nutrients, particularly fiber, that slow down your digestion and allow your body to better process the sugar. One study found eating whole oranges was associated with a lower blood sugar spike than drinking orange juice. Another study is also revealing: Researchers examined whether consuming fruits was associated with higher risk of developing Type 2 diabetes and the answer was no; in fact, the risk was lower. (Unless you drank fruit juice, and then it was higher.)So those natural sugars — they’re fine. “Added” sugars, on the other hand, go through processing that leaves only the pure sugar, without any of those other nutrients, from the cane or corn that originally contained it. These are the sugars that are more concerning from a physical health standpoint. The dramatic spikes and drops in blood sugar that occur when you eat or drink foods high in added sugars may lead to health problems. One major 2023 metaanalysis found that sugary drinks were associated with a higher risk of Type 2 diabetes, hypertension, and heart disease. Scale matters, too: The more sugar you consume, the more dangerous it can be. Dietitians worry about sweetened drinks in particular: Juices, coffee drinks, sodas, and other flavored beverages are an easy way to consume loads of sugar without realizing it.It’s certainly wise to keep an eye on your added sugar consumption. But eliminating sugars entirely would actually run counter to one of the emerging concepts guiding nutrition science: metabolic flexibility. The basic idea is that the better your body can adapt to different energy sources — like fats or sugars, for example — the healthier you are. It’s true that the development of obesity or diabetes can limit your body’s ability to be flexible in this regard… but it’s also true that eliminating certain foods entirely can have a similar impact. One 2022 metaanalysis noted that chronically low sugar intake may have its own adverse effects.Forget “no” sugar and focus on “low” sugarThis sugar fixation is a microcosm of what can be confounding about Kennedy and his Make America Healthy Again movement: They identified a genuine problem worth taking seriously, but the message has become over-simplified to the point that it obscures as much as it illuminates. And the “zero sugar”/“sugar is poison” mindset overlooks important nuance. If you read the fine print of the dietary guidelines (which almost no American will actually do), you would get the right idea; they actually devote a box to explaining what “added sugars” are. But Kennedy often speaks broadly about eliminating sugar entirely from your diet. “What we need to do, probably, is give Americans knowledge about how much sugar is in their products, and also, with the new nutrition guidelines, we’ll give them a very clear idea about how much sugar they should be using, which is zero,” he said shortly after assuming the HHS secretary position last year.That’s how people end up confused and asking questions, like “How do I find fruits that have no sugar in them?” (Impossible.) That’s a problem because there are actually lots of foods that are good for you and have sugar — including “whole foods” like apples, oranges, berries, and milk — that we don’t want to discourage people from eating.Taking all this together, you start to get a clearer picture for how to think about sugar and your health: Don’t worry about the sugar in your fruits or whole-grain breads; those foods also come with stuff that helps your body process the sugar they do have. Do try to limit sugary drinks — even fruit juices — as well as candies and non-whole grain carbs.But also remember that stressing out about food isn’t healthy either; obsessing over foods’ nutritional value and “clean” eating can lead to a form of disordered eating called orthorexia. And we don’t want to introduce those anxieties in our children either. “We don’t want people getting the message that food is bad or that food is a source of concern or a source of anxiety,” says Dr. Amer Al-Nimr, a pediatric gastroenterologist at Dartmouth University. “No” sugar is unattainable — and it’s also no fun. Do what you can to keep it on the lower side, but know that the occasional sweet treat isn’t going to kill you, and fruit is definitely not a problem. And please let yourself — and your kid — have a cupcake at a birthday party. It may not be the “healthiest” option, but it still tastes sweet.