The snacks add up. A medium serving of fries from McDonalds is already about 340 calories--and a medium there is significantly smaller than
average takeaways which come up to 430 calories. That's not even counting the condiments, as ketchup comes in at 15 calories per tablespoon (or 50 kcal per tablespoon for mayonnaise) and kids typically drench their fries in that. Consider also that an average school lunch also ranges between
550-650 calories. These kids are probably going to have another snack once they're home, as well; whether it be fruit, junk, or a dessert after dinner. They eat mindlessly, as a lot of people do. There's a reason Secret Eaters became a thing.
All I can think about is that Slaton video where she claims to have eaten nothing all day, gorges on a massive plate of salad with cheese, bacon, and dressing, then mentions she did in fact have pancakes that morning:
For some reason a lot of people disregard snacks or light meals as calorically significant, but ultimately, all the drinks, snacks, and meals add up. Pair that with how sedentary we've become and no wonder there's an obesity problem.