I would recommend against skipping lunch. Instead, adjust what you bring for your meal based on weather. I just worked all day yesterday in the sun and heat. For lunch, I brought light, easily digested food that would replenish without making me feel sick.

Blueberries and strawberries are great because they have nutrients and moisture. Fruits and veg tend to digest well, even in the heat. Hard-boiled eggs sit well with me and provide some nice protein. I also like the flavored tuna pouches with a few crackers.

I avoid food with a lot of fat/grease or dairy. Neither digests for me well and dairy even makes me feel sick in the heat.

I load 1000 steel parts into and out of a welding press every night, I know all about constantly lifting and moving heavy shit.

Yeah, by the end of the night I'm always hungry af, but as long as I keep my electrolytes up throughout the day there isn't a problem.