Soul food is almost designed in every form to make sure you fail to do anything but get fat. Makes you fall asleep, need to shit, and generally just fatigued. Its like eating Thanksgiving dinner every night. That's without getting into its contents, which provide little sustenance but a lot of padding to keep you gorging but never getting the energy to burn it. Its harder than you think, likely because you've never had a diet that bad to know just how different your "baseline" is from theirs.

Its not an excuse, its that one of their claims to fame is food that is almost perfect at making you fat regardless of any other intentions you may have. Though none of them really eat that anymore, because that requires a functional family unit with a matriarch who has skills, so its entirely a claim to someone else's greatness.

Like how they claim they wuz kangz. Centuries ago, a different group of people might have done something cool so now all of them claim it as a sign of power.

She probably burns more calories maintaining that weight (as in, the energy she uses eating and processing the food) than a normal person burns while doing a light gym-regime for an hour.