In my opinion, eating three meals a day is good IF you are hungry. Your body will tell you what it needs and when it needs it so perhaps it’s time to listen to our bodies instead of other people.

Our ancestors, for thousands of years didn't have an access to ready-to-eat and takeaway foods, moreover they might not had access to any kind of foods for days, so for these reasons, their bodies were used to infrequent eating. Food was seasonal, so they only consumed sugar during the summer/fall (from fruits and veggies), and that was much less than most of the people do now.

There's studies, that show, that when you're eating to often and for extended periods of time, you're actually creating a traffic jam in mitochondira, which means your body is not producing energy. Other studies show, that eating junk food can likely result in a leaky gut (and leaky brain!), which causes inflammation in the gut (and in the brain!), which causes your immune system to work overtime, which leads to experiencing tiredness. It's like a loop, you come home from work, you're tired, so you eat garbage, which makes you more tired, so you eat more often to get more energy, and it ironically makes you even more tired...