Whenever I go shopping, I bring two canvas bags with me and fill them. That's all I can carry, basically. And having to fill a lot of that space with heavy detergent or bulky paper towels means I either need to go on a second shopping trip (which I don't want to do), or decide what things I'm /not/ getting that week.

So sure, some people might end up weaker, but I'm still lugging some heavy bags home with me each week.