how do you tell someone they need to reduce weight?

I had a few patients that were fairly overweight presenting with low back pain. After multiple sessions of treatment their low back pain improved signficantly so the focus of the treatment was on self manaagement and their HEP. The other issue as mentioned before was the excess weight they were carrying. I knew from my initial treatment with my patient that I would have to address this issue. The only problem was that it is a very difficult topic to bring up, and most perople that are overweight are sensitive to the issue. Discussing with my supervisor there were many methods you could use to approach the issue. The very direct way or mor subtley or almost not at all. I approached the topic and fpund that it wasnt that hard to bring it up. The next session however my patient made excuses for this that and the other for not exercising and not eating right. This then continued in the next session and unfortunately there was not much i could do as my placement drew to an end. So how effective was my cozxing and education I wonder? At least I know now how to approach patients with this issue but in terms of how long the impression will last is another matter.