I'm 30 and due to being very sedentary, especially with COVID-19, due to being on a medicine that affects hunger, I'm slightly overweight. I'm taking this very seriously as I've never been overweight before and it affects me very negatively toward my personal self-image.
I have projects to do exercise again beginning in September, but this is a difficult step to me and I'm already having complexes about socializing with sportive people while being overweight. Which is why, I started about a month ago a fight against calories, especially eliminating fat and sugar out of my diet. It's worth noting that my significant other is also overweight and has complexes about that.
I tried to progressively change our eating habits, but so far this have been largely unsuccessful. Despite the fact that I cook so I have a say on our menus, my significant other takes every single opportunity to propose things that are unhealthy. Nothing in the fridge? Burgers on Uber Eats. Hot day? Let’s buy ice cream. Also here is your surprise on-the-bed breakfast with pastry I just bought, etc., etc. I believe he is addicted to that kind of food and in denial that this lifestyle is just unhealthy.
I often ask him what he likes often and what he'd like to eat, but this is kind of hard to reach agreement these days. Previously our way to plan menus is by proposing and discussing what we would both agree to eat. Sometimes we also just take what we know was previously agreed upon.
Today we went on the groceries. We don't usually plan menus until then. When he put fries in our trolley I said nothing, but eventually on our way back I did I was sightly upset because it was not good for the diet I want to make. He got angry at me and clammed up. I felt like I've been clumsy, but I've been softly suggesting healthy things since very long and he didn't take the hint.
Note that this comes at the wrong moment, and he is a bit depressed due to being unemployed and tend to let things slide a lot these days.
How should I negotiate with him that I seriously want to follow a strict diet, provided I'm not ready to cook two different meals every day, and provided he might get upset by a direct approach?
How it actually went
This question drew some attention so I figured I would give an update about what happened next. The fries "incident" came with the realization that dieting was important to me, so I took this as a chance to skip having a conversation with him about dieting because I just didn't know what to ask for there. What I would ask for, being able to diet, would be trivially granted, but the devil is in details and details are not worth great discussions. So, the following days, I focused on controlling my diet and being inflexible about the little sides I was proposed, and tried to offer alternatives for him to eat otherwise.
I came back home from work with a salad I intended to eat while proposing to cook for my significant other. I also asked not to propose me food anymore.
Both things weren't too well received at first because of points raised by some of the replies here : to my SO, sharing a treat with me is important, and this was probably a bit harsh to realize I was rejecting what he thought was nice attentions. I realize that, previously, I bent my diet mostly because I already knew that. But this was not as difficult as anticipated, because I believe my stance was clear.
Another day, he trivially rejected my offer to cook a meal for him when I was having something low calories "You are not going to cook two different meals" and he just made efforts to join me on the diet, without me to insist on that, at least partly. Most of the time, we went on healthy stuff and/or went in the few restaurants that had options for me.
Next trip to groceries, I planned the menus on my own for me, allowing me to plan ahead for diet to keep going. We planned to eat mostly the same.
So, so far so good, I got to diet without cooking two different meals, I can have been very sightly upsetting him at times but I avoided any implication he could have had taken wrong.