The actual issue is that "Ultra-Processed" is EXTREMELY broad and vague.

For example, hot dogs are ultra-processed. Obviously hot dogs are not the healthiest food but also obviously "franks and beans" is a pretty good meal for a tight budget and is something you should be able to get with SNAP.

I think you answered your own question with the last sentence. Have cattle ranchers, chicken farmers, vegetable and fruit farmers lobby for same or higher subsidies than grains.

> a person on a very limited SNAP budget will get less food under the new restrictions ... make it so that fresh produce and other healthy options are cheaper than the junk food

I'm confused by these statements. How are you deciding to measure the quantity of "food"? If you see food as a means to deliver nutrients, fresh produce is already far cheaper than junk food.

From the perspective of your body, you can sustain yourself much better on a smaller amount of nutrient dense calories than a larger amount of empty ones. Obesity is not merely an overconsumption of calories or a measure of food or body mass.