Which of the following statements is not true? a) fad diets often lack scientific research to support their claims. b) fad diets can cause health problems, such as osteoporosis and dehydration. c) the weight lost on a fad diet is usually temporary. d) fad diets require lifestyle changes that teach sensible eating habits that last a lifetime.

[120 total points] (public health) in one of the largest human experiments ever conducted, in 1954 a randomized controlled trial was run to see whether a vaccine developed by a doctor named jonas salk was effective in preventing paralytic polio. a total of 401,974 children (ages 6–9), chosen to be representative of those who might be susceptible to the disease, were randomized to two groups: 200,745 children (the control group c) were injected with a harmless saline solution (a placebo) and the other 201,229 children (the treatment group t) were injected with salk’s vaccine.what was the point of giving saline solution to the children who didn’t get the vaccine? explain briefly.