Re: Do you even lift?
There's several distinct elements to fitness, and some medical professionals are barely competent to judge. For instance, the Body Mass Index is OK as a starting point, at a "do I need to ask more questions" level, but there are people who don't bother to ask the questions. Some athletes have a high BMI, but the mass is muscle, not fat, which has a higher density, and there's a better correlation of poor health with excess fat rather than excess weight.
When I worked on a farm I was heavier than I am now, and the extra weight was muscle. I sometimes had to handle 50kg sacks of wheat seed (and you really need to know how to do that properly). When I fractured my spine, all that extra muscle helped me avoid the need for surgery.
Anyway, the one simple trick to losing weight is to eat less. Exercise helps change the ratio between fat and muscle, and we all need some fatty tissue, Most of us have too much.
Weght training can focus the exercise. As mentioned, running does more for the legs, and weight training can fill the gap. But weight training isn't as good for the heart and lungs, and that seems to be an important aspect. They call it aerobic exercise, and it matters because for a short burst of exercise the muscles use internal resources. At least, they did according to my school biology lessons.
In the end, it's about keeping a good balance, the right mix of food in balance with the exercise. And, while you don't need to be a weightlifter, there are things in the computer business that are heavy enough that you need to know how to use your muscles.
Incidentally, it helps to know how to cook. There are ways in which cooking can really mess with good nutrition. My mother did manage to get away from overcooking cabbage and brussels sprouts.