James Gallagher finds out if we've turned into a nation of grinders after reports from dentists of increased clenching and cracking of teeth. Margaret McCartney answers your feedback about the new weight-loss drug, exercise for your back, sperm counts and then goes for retail therapy with James to discover how useful shopping data could be for understanding our health.

James meets Ian who has Parkinson's disease and hears how ballet has helped with his symptoms, as a major new review of the evidence shows exercise really does make a difference. And microplastics which can be found in drinking water and food stuffs have now been identified in human vein tissue. James unpicks what this means for our health. Presenter: James Gallagher Producer: Erika Wright and Harry Lewis

James Gallagher asks whether a weight-loss drug on the NHS heralds a new era in tackling obesity? He meets Jan who lost nearly 4 stone after being part of a trial taking a weekly injection of Semaglutide for 15 months alongside advice on meals and exercise. However, when people stop taking the drug the weight starts to go back on. Add to that supply shortages with heightened private demand and some doctors think the drug is as controversial as they come. James unpicks the ethical and societal dilemmas against a backdrop of half the world's population projected to be overweight or obese by 2035. Producer: Erika Wright Declared interests Dr Margaret McCartney: "No conflicts to declare." Prof Sir Stephen O’Rahilly : "in the past has been a remunerated consultant and has had research collaboration with Novo Nordisk." Professor Naveed Sattar: "consulted for and/or received speaker honoraria from Novo Nordisk, Abbott Laboratories, Amgen, AstraZeneca, Boehringer Ingelheim, Eli Lilly, Hanmi Pharmaceuticals, Merck Sharp & Dohme, Novartis, Pfizer, and Sanofi; and grant support paid to his university from AstraZeneca, Boehringer Ingelheim, Novartis, and Roche Diagnostics. He was a co-investigator in lifestyle trials such as DiRECT and co-lead for STANDby."

Lower back pain impacts millions of adults every year and, in many cases, diagnosis can be murky. Non-specific pain is personal and complex, driven by factors such as injury, sensitivity and perception. But are there methods to help manage back pain and live a happier life in the process? James Gallagher is joined at a yoga studio in Stockbridge, Hampshire by Emma Godfrey, psychology researcher at Kings College London, chiropractor David Elliot, physiotherapist Richard Husselbee, and yoga instructor, Alison Trewhela to answer all your back pain questions (and takes to the mat himself to try some gentle healthy lower back poses). Producer: Julia Ravey

James Gallagher investigates whether there is a decline in male sperm including the results of his own sperm count analysis. He meets a couple who conceived after having treatment for a varicocele, enlarged veins in the testes that can heat the sperm up and the leading known cause of male infertility. And James is joined by leading scientists in the field to debate whether sperm counts are falling. Producer: Erika Wright