Research has shown that extra force through the spine can cause problems. This force can come from lifting objects that are heavy or awkward. Body weight also adds a compressive force through each bone of the spine.
Forces on the spine are much greater for people with low back pain. This happens because extra muscles contract during lifting to help protect the back. Researchers have measured the activity of muscles during lifting for people with back pain, and it is clear that being overweight adds to the forces.
Weight loss for anyone who is overweight is highly recommended. Weight loss helps reduce the load on the spine, possibly preventing future problems. Talk to your doctor or nutritionist about healthy ways to lose weight.