Your girlfriend is a "grumpy lard ass", how do you shame her into looking better for you.
Well now you have the answer with 10 easy tips from the folks at Askmen !! I've bolded some parts to be helpful to you !!
No.1 - Take her to places where she has to wear a swimsuit
If she seems content staying at home eating donuts in her track pants, why not start taking her to places where she has no choice but to where a swimsuit? As she awkwardly looks around at all the slender bodies having a great time, she'll more than likely vow to do something about her recent weight gain, especially if she knows she'll be back there in the not-so-distant future.
No.2 - Leave "now" and "then" photos lying around
This is a highly effective way to draw attention to the explicit changes to her body as you see them. By consistently reminding her of how she used to look, she'll inevitably be more inclined to do something about her excess flab. Appropriately chosen and strategically placed photos should accomplish this quite nicely. Keep in mind, if she confronts you about trying to shame her into losing weight, the key approach here is denial, as you reply: "Do you actually think I would be that manipulative?" Of course you would, but she doesn't need to know that.
No.3 - Sabotage her chair
Sometimes as men we have to get downright nefarious to get what we want. You might not be proud of stooping to this level, but nothing says "better lose some weight" like a broken chair. After you loosen a few screws or remove some important slats of a chair in which you know she'll sit and subsequently break, sit back and watch the guaranteed dietary transformation that ensues. It will profoundly amaze you.
No.4 - Ask her to wear an old dress
Plan a romantic night out for the two of you and insist that she wears something from when you first got together; particularly something that you know doesn't fit her anymore. This way she'll have to admit to you that she's put on too much weight and can no longer get into many of her old clothes. Follow it up by telling her how good she looked in those days, and maybe she'll make it her mission to get back to that size.
No.5 - Playfully grab her love handles
Ask any man and he'll tell you that he instinctively flexes his biceps whenever a woman touches them. The same thing goes for a woman when you make contact with any unwanted flab: She recoils and feels embarrassment. Use this reaction to your advantage. Even if she thinks that you're too busy at work to have noticed a few extra pounds, if you continually rest your hand on her love handles (or even lightly pinch them), she'll soon realize that you're becoming increasingly aware of something that never used to be there before.
No.6 - Improve your own diet
It's very easy for the two of you to fall into the downward spiral in which many couples begin to replace sexual intimacy with ice cream and cake. Don't let this happen by focusing on your own health requirements and staking your right to a junk-food-free home. It might even be the only way of separating her from the fatty foods which have led to the current problem.
No.7 - Serve her unsatisfactory portions
When dishing up meals for the two of you, try giving her smaller-than-usual amounts. By making her ask for more food, you might succeed in shaming her into an acknowledgment of her recent weight gain, and hopefully to instigate a conversation about what she's going to do about it. If you feel as though you're starving yourself in the process, remember you can always go back for more when she's not looking.
No.8 - Set out on your own weight loss plan
Here's an interesting experiment for you using reverse psychology. A subtle way to tell her she's getting fat is to tell her you're not happy with your own level of fitness and she may begin to open her eyes to the wider picture. By referencing yourself in any plans to lose weight, you're also subtly telling her that you're not the only one who might benefit from a diet. And even if she does see through your ploy, she'll at least appreciate the tact you have shown and will hopefully take the message on board.
No.9 - Sign her up for yoga under the pretence of "stress relief"
This works particularly well if your girlfriend still hasn't worked out the link between an active lifestyle and emotional well-being. Tell her you have found exactly what she needs to help her relax, a regular spiritual cleanse in the form of a yoga class. Make sure you choose an intense, calorie-burning form (power yoga or ashtanga yoga), otherwise she may end up rolling around on the floor a couple times a week with no real benefits. The beauty of yoga is that if you dress it up as a way to relieve stress, she may not realize that she's being tricked into shedding a few pounds, and even if she does, you'll end up with a happier, more self-confident girlfriend rather than a grumpy lard-ass.
No.10 - Buy her clothes that are too small
If you buy her clothes that are obviously too small for her, not only will she finally have to admit that she's putting on weight, but she can easily return them for her correct size. First, she'll have to reveal to you that the clothes are too small. "Oh," you might say, "I thought you were a size 8. Isn't that what you were last summer?" The onus is now on her to do something about it.
...haha oh wait did I say breaking her chair was number 3, I mean TAKE HER ON A FANCY DATE OOOOPS
Honestly when I first read the article I was expecting it to be satire, maybe followed by a 'Do you keep finding hatboxes around the house? 10 ways to keep your lady cooking instead of spending your hard earned money" or even a "9 ways to tell your boyfriend that his penis doesn't satisfy you".
Nope apparently they are serious (though saying number 3 was a joke then changing it isn't a good way to lead your audience guys).
Despite all the unsavory stuff this article draws attention too, I think the worst is that you should manipulate and play games in your relationship. God forbid you actually act like an adult and talk things through.
The sad thing is this almost had the makings of good satire, the chair thing was pretty funny.