Final answer:
The correct statement concerning the news release's study on a diet product is that the results are biased and potentially overstate the effectiveness of the diet due to the small and non-representative sample. For broader and more sustained weight loss, a combination of dietary changes and physical activity is necessary.
Step-by-step explanation:
The correct statement regarding the news release for a diet product company is C. biased, overstating the effectiveness of the diet. This conclusion is drawn from the fact that the sample consisted only of 20 graduates of the company's program who endorse it in commercials. Since these individuals are likely to speak positively about the program because they are associated with the company, their experiences do not provide an objective measure of the program's overall effectiveness. Moreover, using such a small sample size and from a specific subgroup, i.e., graduates who have had success and now endorse the program, leads to a selection bias that may not reflect the experiences of a broader, more diverse population.
Regarding weight loss in general, most scientific studies indicate that successful weight loss is achieved through a combination of diet and increased physical activity. Also, a slow but steady weight loss approach is more sustainable in the long run, and healthy lifestyle changes are necessary to maintain weight loss. The National Weight Control Registry highlights that individuals who have maintained a significant weight loss over time typically engage in high levels of physical activity, adhere to a low-calorie diet, and possess consistent behavioral strategies such as eating breakfast daily, watching less television, and weighing themselves regularly.