I found lowering water intake and upping salt intake (two things I was very happy to do) are what helped my temps, immediately.
My breakfast is a slice of toast with a hefty smear of cream cheese and a boiled egg sliced on top – with LOTS of salt and pepper. Not a lot of calories (could easily double that dose), but the salt and protein keeps me warm and satisfied until my next meal.
Just me, but, being “obese” already (per the “average human” guidelines), I will not experiment with gaining weight. Just can’t do it. Can’t afford a new wardrobe, and can’t wear sweats to a business conference.
This is your body, and your experiment… if what you’re doing isn’t working, try something else. The bottom line: do what makes you happy and enjoy life Today. Re-feed your spirit as well as your body.