On a different angle - why is alcoholism considered sinful by some branches of Christianity, but gluttony (which also gets criticized in the Bible) is basically ignored?
The definition of this sin became rather expansive over the centuries, so it would also cover those who engage in obsessive anticipation of the things they consume, who spend too much on them, etc. One reason for this was that the gorging of the prosperous may leave the needy hungry.
So from that point of view, it seems to me that the sin of Gluttony is still routinely condemned by people of a Christian culture, even if they are not aware of this ancient framework.
Regarding your specific question, I would say that overeating to the point of causing hunger to others is still criticised. At the same time, assuming that there is enough food to go around, eating too much of it doesn’t cause the same negative externalities to others as drinking too much alcohol.
Plus: "It is difficult to get [someone] to understand [obesity, chronic heart disease, strokes, arteriosclerosis, climate change, pandemics, antibiotic resistance, deforestation, environmental degradation, pollution, ultraprocessing malnutrition, and soaring food prices] when his [addiction to Big Macs] depends upon his not understanding it."
Now, "temperance" (= "moderation") and "sobriety" (= "seriousness") are commands, but those are both orthogonal to alcohol consumption. Gluttony is likely related though, depending on definition.
Sects generally form (and mutate) in one of three ways:
1. We're facing some real problem, so I should invent something to fix it.
2. There's something I want to do that current traditions disallow, so I'll make my own traditions with blackjack and hookers.
3. I should be the one in charge.
#1 is a good fit here - the problems of excessive alcohol consumption (and human inability to stop after just a little) are well-attested through the ages, even before automobiles expanded the ability to kill others.
That being said, its one of the capital vices and many people focus on the mortal sins first since venial sins can be curbed easier.
There's often discussions about it at Churches, especially during Lent.