Trouble is the advice from Tam Fry and the National Obesity Forum is fundamentally flawed.
These are people who have a vested financial interest in promoting and maintaining obesity levels
that is why their advice deliberately and knowingly avoids dealing with the main factors, refined carbohydrate, omega 6 pro inflammatory seed oils, and caloric sweeteners (sugar/hfcs) that all promote chronic inflammation and prevent successful weight loss strategies working over the long term.
By putting the blame on the obese or their parents and relying on calorie restriction and more exercise (calories in calories out) they miss the point that control of metabolism should be regulated automatically by effective gut flora and mitochondrial functioning.
So long as you maintain a pro inflammatory gut environment you maintain gut flora associated with obesity which extract the maximum amount of calories from the food you consume. Only when you reduce chronic gut inflammation will you allow the gut flora associated with lean bodies to thrive.
A healthy gut is the hidden key to weight loss