Pretty sure it does. Given how nasty it tastes, I lose all my appetite when I try to use it as condiment.

I remember a recent study that claims skin exposure to the sun is necessary/needed to burn fat. I'll try to find it and update this comment.

Edit: this seems to be the study https://www.nature.com/articles/s41598-017-16689-4 The gist of it is that sunlight shrinks fat cells, but I might be oversimplifying it

Maybe, unless you use sunscreen that's also an endocrine disrupter, then all bets are off.

No. Not necessarily.

Also details and interactions matter. From paper:

Our study revealed that UVB exposure enhances food-seeking behavior in males via ghrelin and a process that is prevented in females. We found that p53 mediates transcription of ghrelin in skin adipocytes and that estrogen interferes with the p53-mediated transcriptional activity, thus blocking the positive effect of solar exposure on food-seeking behavior in females. ...

The increased hypothalamic expression of the orexigenic pathway indicates that ghrelin activated this pathway, which translated to increased food intake in males. As ghrelin serves as a peripheral satiety signal, its concentrations change in response to environmental cues and reach hypothalamic satiety centers.

However ...

A direct link between the skin and the brain was demonstrated in a study showing that UVB exposure induces the release of urocanic acid from the skin to the blood, which is converted to glutamate in brain neurons, leading to improvements in motor learning and object recognition in mice61. Ghrelin enhances learning and has anti-anxiety effects and neuroprotective functions32. It will be interesting to further study whether skin-mediated induction of ghrelin production directly improves brain function, such as memory and learning abilities and whether there are additional hormones released from the skin that modify human behavior.

UV is a well-established carcinogen, but avoiding the sun rays adversely impacts human health, too11. Since ghrelin has anti-inflammatory properties62, halts heart muscle wasting63 and decreases arterial pressure64, ghrelin may be the mechanistic link between solar exposure and cardiovascular disease reduction11. Moreover, ghrelin enhances insulin sensitivity in metabolic syndrome patients65 and in animal models of type II diabetes66. Patients who suffer from appetite loss, which affects their health and recovery rate, such as patients undergoing chemotherapy67 patients, should benefit from treatments that induce ghrelin production. Indeed, ghrelin administration during chemotherapy has been shown to increase food intake and appetite68. The ghrelin receptor is expressed in the brain69 and in peripheral tissues (that is spleen, myocardium, thyroid, pancreas, and adrenals)70. In addition to its function in regulating energy homeostasis32 and the functions mentioned above, ghrelin also mediates glucose homeostasis71, muscular atrophy72, bone metabolism73, stress and anxiety74, adipogenesis75 and the immune system76. Therefore, the various role of ghrelin, might be also observed upon UVB/solar exposure and will be interesting to investigate. Thus, our study suggest that the use of phototherapy might be extended.

If you mean, is goopy and smells like a chemical factory, then yeah, I guess it'd turn off one's appetite a bit. Wouldn't want to hold food in the same hand I'd rubbed it on with.

If you smear mayonnaise all over your skin like the people around here do, it's bound to cause problems with keeping food down.

If you use the old school white zinc oxide cream and keep it on your hands, you won’t eat anything out of disgust.