Never mind the statistics on keeping the weight off, though that too is a serious consideration, weight loss without strength training WILL put you in a far worse position as far as long term health and wellness prospects.
We take for granted our skeleton, muscles, ligaments, tendons and cartilage. But your body sees them as high cost dead weight. We lose 1lb per year on AVERAGE when we don’t stress them with heavy loads.
When you purposely make the body shed weight without strength training, that 1lb gets amplified and the lean tissue loss is accelerated.
You can easily see this in the builds of people. Those who have lost and gained and lost and gained end up with increasingly softer or toothpick arms and legs with an increasingly large center mass, even if they’re lighter than they once were.
Most risks of fall and loss of resilience with aging have to do with incredible weakness. It won’t matter if you’re 120lbs when you’re 80 if you haven’t sufficient muscle mass.
Don’t lose weight without heavy strength training.