heres some insight on diet..
the number one factor as to whether you will gain size or lose it, is calories. all of us have a "calorie maintenance level." meaning that on average, each day you burn X amount of calories as you go through your day. in order to gain weight you have to have a calorie surplus. maybe to put on a LB a week, you need to ingest an extra 100 calories a day above your maintenance level. likewise, in order to lose weight you must have a deficit. maybe youd need to have 100 less calories in a day.
this illustrates the importance of diet ...
if you have to have 100 less calories each day, you have two choices. you could BURN the calories by doing cardio, or by tracking your diet simply eat 100 calories less for the day. thats why you see people focusing so much on the specifics of their diet, when trying to reach very specific weight goals.
arguably the second biggest factor for you will be protein. in order to build and maintain muscle, you need protein. generally 1.5grams of protein for every pound of bodyweight. if you weigh 185lbs, that equates to 277.5 grams of protein each day! a lot of people who arent growing or building muscle the way they want to, even though theyre hitting the weights hard, simply arent eating enough.
as you can imagine it might not be very practical or conveneint to eat nearly 300 grams of protein each day. this is why so many take advantage of protein powder/shakes. 20-30 bucks for a 5lb tub of it, each serving gives you roughly 30 grams of protein that you can drink on the go. it can also be less expensive than only eating fresh lean meat for protein. but the fresh meats should definitely be your primary source.
and as far as the RDI goes, think about it like this. its calculated off a 2,000 calorie diet. its based on the average lifestyle of an average man. he works monday through friday, 9-5. runs errands on saturday, sleeps in on sunday... watches some football, drinks beers with his friends and then calls it a week. if this average man isnt taxing his body much, he doesnt need to refuel it with much.
we, on the other hand are not average men. honestly! i work full time, have a business ive been building part time, lift 3 days a week, play basketball and go hiking a couple times a week, have lots of healthy ... ahem ... with my girlfriend, spend time with family, etc. we live very active lifestyles, and we demand our bodies to keep up. we have to support our bodies with vitamins and nutrients to keep them going.
as an example, think of your immune system. if you dont keep it strong by taking vitamins and whatnot, it will be weak. when youre under stress or if someone around you has a cold, youre that much more likely to get sick. whereas if you always taking your multivitamins and sleeping right and generally being healthy and aware of youre body, your defenses will be strong. for myself, now its to the point where my gf can have a cold, and even though we live together, sleep in the same bed together, have sex etc, i dont get sick. people from work dont get me sick either.
i take pride in that!
and i know that if i just stuck to the RDI, it wouldnt be that strong. as far as vitamins, i would recommend a quality multivitamin that gave you hundreds, and in some cases thousands percent of the RDI.
and as far as supplements, theyre just that: SUPPLEMENTAL. they are the icing on the cake. not the cake itself. the core focus should be on eating good, hearty meals. drinking lots of milk, juice and water. sleeping 8+ hrs every night. stretching. a solid, practical workout routine. focus on the fundamentals and you will start building a strong foundation. the only supplements you should worry about to start is a quality multivitamin, and possibly protein powder. the vitamins are number 1. protein powder can make it easier it get all the protein your body will be needing. after that... do some reading on fish oils. and if you want to spend more money on frostings and desserts, THEN buy more supplements.
theres a few mainstay supplements that will round you out. but 99% of supplements out there are more marketing hype than anything else.
good luck
-slb