Beginner's health and fitness guide

Originally by sean10mm, modified and updated by Liam Rosen

This was originally posted on the the Something Awful Forums. Since sean10mm rarely posts there any more, I'm maintaining and updating this guide for now.

Questions? Suggestions? E-mail me: liamrosen@gmail.com
CONTENTS
PART I: OPENING Q&A AND GENERAL MYTH-BUSTING
PART II: MINDSET
PART III: DIET
PART IV: EXERCISE
PART V: MEASURING PROGRESS
PART VI: MORE QUESTIONS & ANSWERS
PART VII: THANKS AND RANDOM CRAP LIKE THAT
PART I: OPENING Q&A AND GENERAL MYTH-BUSTING
I don't want to become some huge bodybuilder freak, I just want to get in better shape and look better. Should I read this?

That's what this guide is for. It's a basic guide to diet & fitness for beginners who want to get in better shape. If you want to look better, improve your overall athletic ability, or just improve your health, read on. If you're a bodybuilder or athlete, you probably already know most of this stuff.
I'm a female; does any of this apply to me?

All of it applies, actually. With very few exceptions, the principles of diet & exercise are the same for men and women. And don't worry about becoming a manly she-beast from lifting weights; most women can't gain muscle at anywhere near the rate of men, no matter how hard they lift. Remember, female bodybuilders are lifting weights constantly, eating twice as much as you and taking male hormones. Getting huge doesn't just happen to men, let alone women.

A word of warning: many female fitness magazines tend to be really idiotic and gimmicky, fixating on things like "spot reduction" that were disproved 50 years ago, and trying to sell whatever their advertisers are pushing that month. If the magazine shows a skinny bimbo doing curls with 5 lb dumbbells, you should probably throw it in the trash.

There are a few female-specific notes in this guide, but they are rare, because the differences are almost always insignificant for the purposes of promoting general fitness.
There is all this contradictory advice! I'm so confused!

The methods for improving your fitness are actually very well understood, and aside from minor matters of detail have changed very little in the last 30 years or so. Most of the seeming contradictions in fitness advice are really just pissy arguments over matters of detail that need not concern you, or are due to hucksters peddling utter garbage. There is almost universal consensus among knowledgeable people about what works and what doesn't. That's what this guide is based on.

There are two basic considerations: diet and exercise. The same advice for each applies to almost everyone. The exceptions are at the extremes, e.g. the very obese needing to lose immense amounts of weight to stay alive, and the people pursuing extreme levels of performance or muscular development. Both of those are beyond the scope of this guide.
Can't I just exercise a fat part of my body to make the fat go away? Can I just do a bunch of sit-ups to make my gut go away?

No. So-called "spot reduction" is a myth. You can't exercise one part of your body to make fat in that part of the body go away; it doesn't work that way. You can only reduce your overall body fat, not make it go away in a specific area.
I want to get abs, what workout should I do?

Having visible abs has very little to do with doing abdominal exercises, and a whole lot to do with how much body fat you have. Doing lots of ab exercises is irrelevant if your abs are covered in a layer of fat. To get abs, you need to get your body fat down with diet and exercise.