By Martin Bagot Slimmers on weight loss jabs could gradually stop them without piling weight on, medics say. Many doctors believe the obese must take the weekly shots for life. But a study of 2,246 people suggests injections can be prescribed at much lower doses and even stopped if patients get help to improve their diets and lifestyles. Some 200 who cut down and stopped had not put weight back on six months later, the European Congress on Obesity in Venice heard. Dr Henrik Gudbergsen said: “We used to think these drugs are for ever or you put the weight back on. Now, we know that’s too simpli…