Weight reduction has been shown to be helpful for patients with lower limb joint pain. Unfortunately it is easier to plan to lose weight than to do so!
There are many weight loss books and many diets. I have read books that tell me that fats are bad, others that carbohydrates are the enemy and yet more that blame protein.
The best resources I have found focus on the amount we eat and why we eat rather than the specific food. We eat for many other reasons than hunger. It is changing these behaviours and controlling portion sizes that seems the best solution to me.
Patients often report weight gain after injury or arthritis. Often they feel that lack of exercise is the cause. While this is one factor, a bigger issue is that food consumption does not fall when activity falls. People often eat for comfort when they are unhappy or in pain and this exacerbates the problem.
Personally I have found the book "Mindless Eating" to be a superb read. There is an excellent website associated with this book.
In a review of 60 diets by the American magazine "Health" the Structure House Diet rated number one.
Both of these books focus on changing eating habits. If you have struggled to lose weight I suggest having a read of them (they worked for me).
Mindless Eating: Why We Eat More Than We Think
Brian Wansink
The Structure House Weight Loss Plan
Gerard J. Musante
It is also useful to know what your ideal weight is for your height. The simplest way to determine this is to calculate your body mass index or BMI. You can calculate your BMI here.