Many people know that most ultra-processed foods are not healthy. But the goal of cutting down on them can be so challenging that the majority of these attempts fail. Why? In my Food and Addiction Science and Treatment Lab at the University of Michigan, my colleagues and I are investigating one largely overlooked factor: these ultra-processed foods may be addictive, sharing more in common with tobacco products than with whole foods like apples or beans. Tobacco and ultra-processed foods alter mood similarly by increasing pleasurable feelings and reducing negative ones. The high levels of refined carbohydrates and fat in ultra-processed foods powerfully activate reward systems in the brain. Ultra-processed foods are highly reinforcing — they can shape your behaviour to keep you coming back for more. For example, teachers and parents use ultra-processed foods to reward good behaviour in children to increase the likelihood that kids will continue to behave. In rats, researchers have repeatedly found that sweet tastes are more reinforcing than even highly addictive drugs, like cocaine. The addictive nature of these ultra-processed foods undermines consumers' free will and health in the service of profits. Yet, there is an important difference between tobacco and ultra-processed foods. We all have to eat. No one can opt out. In the case of tobacco products, it will likely take industry regulation to chip away at the popularity of ultra-processed foods.