Have some diluted vinegar after meals. It's the world's original "miracle tonic", with anecdotes dating back to antiquity, and mostly acts to facilitate digestion, which can smooth out indignities within your actual diet and therefore leave you feeling better rested and fed with lower intake. You don't need to take vinegar at full strength to see benefit, so I often have it with bubbly water.

(If you actually search around the web for the topic of vinegar you will discover the apple cider vinegar cult. This is a thing that got started in the 50s from a book author who spun his marketing as old-timey folklore. ACV is not significantly different from other vinegars, though some may prefer the taste.)