Depends on if they’re actually overweight, and how they’re handling it. If they’re wallowing in self pity or engaging in unhealthy behaviors that suggest an eating disorder, then I guess you approach the actual issue instead (i.e. the depression, the eating disorder). If they’re just trying to psych themselves up to exercise more or eat better to shed an excess 15 pounds then support and encourage them.

In this context, I think “fat” means “fatter than I’d like to be” and isn’t an objective statement. If there’s no medical reason against it, I’d volunteer to make lighter meals and/or do active things like hiking or whatever we both like. If they’re a recovering anorexic or something, I’d probably try to talk them into seeing a professional.

These problems are often caused by psychological problems, such as bad experiences in their past, for example being bullied in school for being fat.

You might want to talk with your partner about that.

Exercise with them gently. Get their friends to acknowledge their svelte physique (that’s a strong maybe).

Feeling fat isn’t always about feeling/being fat, it’s about being comfortable in one’s skin and at one with those closest.

Well I am on the other side of this, I feel so fat even though objectively not overweight at all (BMI of 22, and pretty lean) because I was underweight a long time so in a relative sense I feel fat. I also feel better than I ever did when underweight, physically, and my bone mass is a little better (which is supposed to be impossible to achieve at my age) and that pisses me off, I want my healthiest weight to be the size I like better.

I don’t think it’s good for you to enable them in losing weight, no. Unless you are 100% sure they are not falling into disordered eating. It’s their body, you can’t control that but it’s fine not to support or help them with it.

As someone prone to eating disorders - the suggestion to work out is solid. I find it much better to focus on athletic goals and just let form follow function. It’s good to be able to feel good about what my body can do.

Depends, how fat? Like I’d say I’m fat if I’m not fitting in my clothes and that’s probably 4kgs extra. If I had a partner I’d expect support to get to my desired weight again. Even if I’m still within an acceptable BMI with or without those extra kilos. If I was going too underweight I’d expect them to talk me back to my senses.

Depends on how debilitating it is, if its bad enough, therapy might be a useful option.

Body dysmorphia about weight might need a bit more help than you can give as an individual.

It might not meet the criteria for that, but worth consideration.

Edit: to clarify, dysmorphia like this is where the brain refuses to acknowledge the relatively objective reality of a “normal” weight.

It’s often one of the underlying causes of bulimia/anorexia and the converse.

I’ve lost about 55lbs over the past two years and still have 15-20lbs before I reach my goal weight. I was overweight.

I know my partner would still love me if I didn’t lose the weight, and was never bothered by my body the way I was. It’s not about what my partner thinks of me. It’s about what I think about myself, and frankly society. Society is kinder to me after losing weight, and I suspect I’ll be treated even better in the world once I hit my goal weight. People are so happy and proud of me (for essentially skipping meals.)

I don’t know how to convince someone to not crave the kindness and compliments now that I get them.

Once I’ve reached my weight goal, it might be difficult for me to stop trying to lose more. To see how far I can go. I really had to change my mindset to lose weight. It will be difficult to adjust or alter that mindset once I reach my goal weight. It will be a process to learn how to change my food behaviors and find the balance of not over eating or under eating.

This probably doesn’t answer your question.

Have you ever heard the phrase “You can’t reason someone out of an opinion that they didn’t reason themselves into”? If they’re objectively not fat, than what they’re really saying is they feel like they’re fat, not they they think that they’re fat. That can be for a whole host of reasons, but arguing facts with them won’t help. Far better to have discussions with them about why they feel that way and why they’re focused on it. Ultimately it’s an issue they have to resolve themselves and not something you can convince them of.

Just keep telling them that they are beautiful.

Someone with body issues of any sort just need to have their self-esteem reinforced.

Targetting their specific issue can seam insincere. Just telling them that they are beautiful is enough.

I allow them to feel fat while still demanding they provide evidence if they actually insist they are overweight.

I feel fat even when I’m in a healthy weight range; I think that is patriarchal social programming. I don’t think you can control how someone else feels. But when they start really getting down on themselves, I encourage them to either find evidence that they are overweight and then set goals to deal with it. Or, they can’t actually prove it (ie. They are healthy weight/waist) and then we deal with overcoming the social programming.

Not perfect, but it works for me and my partner. Mostly deals with accepting how we feel and making a plan about it.

Feeling fat isn’t just about being fat, it’s about knowing you could be better for your health.

If a partner says they’re feeling fat, it probably means there’s something they think they should be doing but they’re not doing.

Maybe they want to eat better, maybe they want to exercise, maybe they think they should be doing these things even though they don’t want to be doing these things.

When the partner emotes to you, you can use that as a point to help them improve, or go on a fitness journey with them, or just reaffirm that you find them attractive. It’s just an open dialogue option

Do what it takes to get them to a doctor and let them handle it. For example: "I want to support you, but I am no expert. Let’s see a nutrition specialist to see what the best course of action is. Personally, I think you are not too fat, but if there is something you want to change, let’s do it right.