Mmmm peanuts!! Trouble with those I find is they are way too salty and 40g is never enough!!! Peanuts are my one weakness - I could happily eat 500g in one sitting (yup, thats nearly 3000 calories!!)
If you can just eat 40g, you're lucky...abstinence is the only way for me unfortunately, I just don't know when to stop. Haven't eaten peanuts in 6 months
If you can go for nuts from a health store as oppose to KP nuts as they tend to have more saturated fat. Also with your tuna try and eat tuna steaks (different thread) as they are genearly better quality