Sometimes yes, sometimes no., The diagnosis of Type 2 is so broad that it is becoming meaningless. Some things you can control through activity, diet or lifestyle changes. Some not. It is not always the patients fault. And for some conditions getting lumped into this diagnosis the "usual advice" on diet and lifestyle is wrong and make things worse. So "certainly" is not so certain especially when understanding what is actually going on with the individual patient's body is not sought.