It definitely is true. Macros are macros.
Another film maker did an opposing documentary "Fat Head" eating fast food daily for a month. Except he kept carbs to 100 grams per day (how?...lol) and his daily calorie intake to 2,000 calories.
He lost 12 lbs and his bloodwork improved.
Now... because of how calorie dense fast food is... It would be brutal to only eat 2,000 calories per day, you'd be hungry all the time. But its doable, just not easy. And most people in American society would never have the discipline to stay under 2,000 calories with fast food.
Maintaining a 2,000 calorie per day with chicken and vegetables is much easier due to having more food to eat. I know I have definite trigger foods that cause my body to want more and more... never feeling full. Potato chips are one... Fucking donuts. I don't even eat that first one, because I know my brain was kick in the response to devour the entire box.
I get what both of you are saying. Technically, you're right... You could eat "healthy" with fast foods, but you'd have to be disciplined as fuck and ready to be miserable from feeling like you're starving. It just isn't sustainable for most people.
Maintaining a healthy lifestyle is much easier eating "healthier" foods because you won't be so miserable all the time from feeling hungry.
For the record, I was arguing against the assertion that there is no such thing as unhealthy food. There are literally "foods" that were pulled off the market because they caused medical problems. I mean I don't understand why anyone would make such an assertion in a World where that has happened more than once. There ARE such things as nutrient dense foods, nutrient deficient foods, and its not at all controversial to say that when a type of nutrient can be and IS used for anything other than energy production, all bets are off. Fat calories do not go solely to energy production. There are also negative calorie foods (that have high TEF), some of which are nutrient/calorie dense, some are nutrient deficient. Consuming "healthy" food doesn't need to be miserable, as we have a warped idea of what "healthy" could be for us. Most people picture greens (salad), endless fruit that you get tried of, boring chicken or fish. Then you hear tons of misconceptions about things like eggs, cheese, red meat, all stemming from the decades-long "low fat" craze that the US Government adapted after the McGovern Committee, and exported to the World. Misconceptions full of outright bullsh*t, like the notion that cholesterol on your place becomes cholesterol in your body, it doesn't.
People come with all kinds of genetic conditions that affect how they function. Generally their bodies should do X or Y, but then you'll come across people whose bodies just don't quite respond that way and their dieting habits need to be tweaked. And this is in the context of optimal health based on things like athletic performance and blood work, markers for problems that could pop up. It's not controversial to say that some foods are just trash, nutrient-deficient empty calories that are good for barely keeping hours alive at best. It's not controversial to say that some foods are better tolerated by some people, and not so much others, based on their genetic makeup. The amount of work you would need to do to even look like you're overcoming food being garbage is effectively impossible for the average person. The best argument one could make for a population on-average, eating shit food and looking good are prison inmates, but they workout for an absurd amount of time in the day.
CICO is definitely one of the most valid components of weight gain or loss, but it's also grossly oversimplified, and over-stated when it comes to getting people to their goals. It sounds really smart, though, just like saying the key to having a lot of money is spending less than you make. It's a fundamental, undeniable truth, but teaches you almost nothing about the intricacies of managing finances. Managing optimal health is just almost never as simple as "eat less, workout more."