Answer
To know which type of food would make an animal grow faster, an experiment must be conducted using two animals of the same species and the same age group. For example, we can use two rats. These animals must be placed in the same shelter. For three weeks, one rat is fed with cheese, while the other is fed with bread. Every week, the rats are going to be measured in terms of height. The results are going to be compared to determine which food has helped the animal to grow at a faster rate.
Work Step by Step
One way to approach this hypothesis is to first choose an animal whose growth can easily be evaluated. To do this you would have to research which animals would be easy to experiment on; since this involves two different variables, it would be better to have two different test subjects. So it would be necessary to find a very simple animal (maybe an amoeba) whose traits don't change much from one individual to another. Next, you would have to research what that animal usually eats, and then try to figure out why it eats what it eats. Then, research and try and find another food that has the same nutrient in a greater or lesser value. Then, using the two types of foods, get two different test subjects. Feed one of them one type of food and the other the second type. Then, measure their weight (or any other factor like size) to see which of the two subjects would grow faster. Remember to feed each subject the same amount.