My mom relies on candy, cookies, and sometimes brownies to get a boost of energy. At one point, she was relying on donuts to help her have the energy to get a shower. She would speculate what the key ingredient is in those things that would help her. Chances are, the ingredient is sugar and sugar isn't a reliable source of energy.
However, it should be noted she does eat meals and it's not 100% sweets all the time.
She drinks 2 cans of Coca Cola every day. There were some days where she would have 3. At one point last year, she decided she would have just 1 can each day. That lasted for just a few days. She went back to 2 cans so she could "have a pick me up" with the 2nd can.
She needs to be told that junk food isn't helping her get better by any means and she needs an improved diet, but I don't know who to turn to and if she'll take the advice and ditch the junk food. The junk food has done more to expand her gut than restore her mobility. She's yet to reach out to a dietician or nutrition who would know what to recommend. I'm 100% positive every dietician and nutritionist in the world disagrees with her when it comes to relying on sweets for energy.
Sugar is an energy source. The problem is its a fast high and then it plummets and causes you to then be down with no energy.
You don't say how old Mom is. Seems like she has set in her head that to be able to get anything done she needs something sweet. Not sure how your going to break that thought. I found to eat right you have to be willing to cook it. If Mom lives alone, thats hard. I would get her to cut down on the sodas. One a day to start. Then work on the snacks. But, as a 72 yr old I am very aware I don't eat right but I also do not want to eat Vegan, which is what my daughter is and preaches plant based. I eat very little and when I do eat I want to be satisfied and not satisfied eating certain "plants". 😊
When my BIL was undergoing chemo, he lost much of his sense of taste. Only things with very strong flavors enticed him into eating. Sweets were one of the things he could taste, and much more so from junk foods than things like fruit.
Another factor in some people who forgo healthy foods for junk is financial reasons. Junk foods and highly processed foods are much cheaper than healthier food choices. A can of string beans, for example, is way cheaper than fresh string beans (unless the beans are "in season"). Does your mom have financial issues, or is she worried about having financial issues in the future?
Have any of her doctors expressed concern with her choice of diet or her weight gain? When my MIL had lung cancer, her doctor actually encouraged her to gain weight, because the chemo she was taking did such a number on her appetite as well, and she was so incredibly tiny to begin with (she tipped the scales at 100, but only if she was holding a bowling ball at the time).
If you really think that her diet is detrimental to HER individual health, and she will not listen to you about it, you might need to enlist the aid of one or more of her doctors. But don't be overly surprised if they tell you that they have much bigger concerns about her overall health than her diet, and it might be they are going to pick THAT battle over the battle of her eating habits.