I'm 42 and was always a fat fuck with no muscles. I've made some minor changes in my life, not even working out, and I'm developing muscles better than I ever had. I've lost about 45 pounds. I didn't even make all these changes at once. Here's what I do:

>carry around a steel water bottle full of filtered water
>drink more herbal tea, sweetened with a little honey if I feel like it
>if I eat something sweet, make sure it has real sugar and not artificial sweeteners
>eat more fruit. Frozen is fine, especially for smoothies.
>drink protein shakes from time to time, if I remember to do it.
>drink whole milk not skim
>eat yogurt with granola and a little local honey from a beekeeper. Thicker yogurt is better.
>use high butterfat butter, not margarine, ever.
>drink psyllium husk
>drink alcohol less frequently, but don't cut it out totally
>try different brands of pickles. I like Grillo's.
>avoid dehydration
>avoid excessive caffeine