I am always keeping my eyes open for helpful tips on this subject. I am told that our metabolism slows as we age and that even if we eat the same we will probably gain weight over time. Conversely if we eat the same but increase our metabolism we should lose weight? Well not so fast depends how we increase metabolism. One way is to gain muscle (which as an aside is pretty important as we age). You could start an RT program and find that you gain weight due to increased muscle mass. Your clothes will probably fit better.
I came across this short video clip on Global News. Watch it for the key messages around metabolism, avoiding crash diets and the importance of RT.
https://globalnews.ca/video/7642809/increasing-metabolism-after-40/