I don't think lazy is the best framing. I do think most people have bad habits around sleep, diet, and exercise. It's difficult to change these habits even if you have a good mentor, which most people don't. It's also very human to ignore advice and take the path of least resistance.

I have been in that place myself for most of my life and for able-bodied people it is possible to get 150 minites of low-intensity excercise a week, more sun, leafy greens, a can of sardines each day, and such low-effort interventions which have a high impact on health and well-being.

My advice to those people would be to start slow and not beat yourself up about having a milkshake and such. It takes time to build habits and good habits tend to cascade and encourage you, especially when you are happier with what you see in the mirror.