I lost a fair bit of weight last year going plant based and then stalled out, even though I should have been losing weigh per my calorie counter program (cronometer). I started losing weight again since March after paying more attention to things like my zinc and vitamin D levels for boosting immunity for Covid19, despite not lowering my calories significantly or exercising more. My heart rate had been pretty low and that went back to normal to even high range sometimes as well.
Interesting related articles on zinc and weight loss -
"The placebo group lost less than one pound while those taking zinc lost almost four pounds."
"In simple terms, not enough zinc can impair thyroid function, resulting in a slower metabolic rate, which can make it harder to burn fat. To put that into perspective, a related case study found that one woman’s resting metabolic rate dropped by 527 calories a day due to a zinc deficiency. That’s 3,689 calories a week, or more than one pound of pure body fat energy-wise.'
I hurt my shoulder exercising and DH was making the meals for awhile. I didn't want to bother him to make lower cal versions of everything, so I just ate what he was making. But I still lost a pound even with eating more calories than I used to and no exercising at all while my shoulder healed.