> An hour of intense exercise might burn 500 calories, and it’s very hard to keep up that level of effort for even one full hour — especially if you’ve been sitting in a chair all day for years on end.
This is probably true, though it doesn't factor in the effect of muscle mass and "afterburn" on resting metabolism. Muscle is expensive, that's why your body gets rid of it quickly when you don't use it. And you spend a lot of calories replenishing energy stores and repairing your muscles in the days after your exercise, because that's far from a 100% efficient process.
If you're male and an absolute beginner (as sitting in a chair all day implies), you can gain significant muscle mass with just 90 minutes a week of strength training.
The direct calorie expenditure of exercising that much may be minor. But you will soon be burning an extra 150kcal/day in afterburn and muscle maintenance just sitting on your ass on your off-days. That adds up to a nice beer budget.
Intensive strength training isn't for everyone though, I can see why a guide for the lazy person might leave it out. But if you're even slightly more of a minmaxer than just lazy you should consider it, given all the other additional benefits of exercise.
Finally the protein paragraphs are very spot on. Especially now quality protein shakes are cheap and easily available. One of those (125kcal) fills me up like lunch, and two like dinner. They're an incredible weight loss hack.