And that's how my eating disorder began. I'm constantly feeling guilty for eating because gluttony is a sin, and I feel like I don't deserve to eat because I'm a sinner.
This is one of many things that comes down to a sense of balance.
A lot of traffic enforcement in the UK is done with cameras. In particular speed limits are enforced with cameras, as are bus lanes and red lights. The camera has no capacity to reason, no capacity to warn someone of the rule, they simply take a picture and you get a fine in the mail. So if you've got an ambulance behind you with its lights and sirens on, and you ease slightly through the red traffic light to let it get past (it's allowed to jump a red light if the road is clear, which it should be because traffic should yield to it), the camera doesn't see that you went through slowly and cautiously for a very good reason, it just registers a violation and you get a ticket in the mail. If you're speeding the cameras don't give you a warning, you just get a ticket in the mail. Sometimes for good measure you can drive down a road for miles seeing warnings of speed cameras on every other light pole but no indication of what the speed limit is. The signs are clear - if you go over a certain speed you'll get a ticket but we're not telling you what that speed is. It's counterproductive in so many ways it's just not funny.
If you think of God in the same way then following God becomes an exercise in fear and frustration. If you cross an invisible line then you sin, but there's no definition of where the line is so you end up taking a best guess, then worrying that you might be wrong and making a more conservative guess, and there's no end in sight. Scripture doesn't clearly tell us what differentiates "eating" from "overeating" or what differentiates "overeating" from "gluttony" so it would seem that either we're dealing with an invisible line with eternal consequences for straying even slightly over that line, or some other means of figuring what's what.
We need food to survive. We don't need to eat dessert after our meal to survive. So is it sinful to have a slice of pie after our main course? What about a second slice of pie? What if we've had seven slices already and decide to just finish off the rest of the pie? If we're worried about how many slices of pie we're eating, logically it must matter how big those slices are? If you cut a pie into 8 and eat two slices you've eaten more pie than if you had cut the pie into 15 and eaten three slices.
A lot of the time I think we need to make a difference between an occasional indulgence and a habitual indulgence, as well as our reasons for doing something. Most months at my church we have a fellowship meal, where people bring food to share and we all eat together. There is usually enough food to feed twice the number that turn out. I'm fond of desserts, and will often have a piece of several of the desserts on offer (usually what I do is sample a couple of them, then go back for seconds once others have had chance - it seems crass to load up as many plates as I can carry all at once). Is that sinning? I don't think it is - the food is there to be shared, and it's not like I eat until I'm sick, nor do I eat like that on a regular basis. Likewise when I visit my Portuguese friends their approach to hospitality is to feed you until you can barely eat anything else. To them their job as hosts is to make sure their guests have eaten well and they would consider it quite rude to accept an invitation to eat with them and then not actually eat with them. I don't think it's useful to argue that such a situation demands that you choose between offending your hosts or taking a greater risk of crossing an unknown line.
Jesus ate and drank with sinners. He noted how when he came eating and drinking people called him a glutton and a winebibber (which suggests he was also drinking wine). But we know Jesus was sinless, so we can reasonable assume that eating and drinking in sufficient quantities that some called him a glutton and winebibber isn't actually sinful. That suggests the issue is more about motive than specific quantities.
I'd draw a rough parallel with the issue of drinking alcohol. Jesus being called a winebibber suggests he partook of a glass or three at times so we can reasonable conclude that drinking wine isn't sinful. Paul told the Ephesians not to be drunk with wine, so we might consider limits where drinking wine (or, by extension, beer or spirits or whatever else has alcohol in it). We could try and figure out what counts as being "drunk" but that becomes an impossible task with so many possible scenarios. If you're a commercial airline pilot about to fly you'll have a very strict rule about how much alcohol you can have. If you're planning to drive home you'll have a specific limit, even if less strict. If you're at a friend's house and stopping overnight you don't have to worry about drinking and driving. But what counts as "drunk", and how do you know that this particular drink will make you "drunk" unless you either drink it to find out or refrain completely just to be safe. We can look at Paul's reasoning - he says not to be drunk with wine because it leads to debauchery. The idea isn't to create a prohibition against crossing some arbitrary and vaguely defined line just for the sake of it, more to avoid doing something that will cause other problems. The way I see it, if you're eating and drinking with friends and suddenly realise the wine has gone to your head and you feel a little fuzzy you haven't sinned. If you've drunk so much you start lusting after your friend that's different. If you habitually drink in order to get drunk that's different. If you drive home despite being over the relevant limits for drinking and driving that's different.
Ultimately a lot of this will come down to how you see God. Do you see God as a loving father who wants the best for us, or as a strict disciplinarian who is watching our every move looking for a reason to punish us?