They will likely become constipated because there is no fiber in that diet.
They may end up with osteoporosis because the phosphorus in all soda, including diet soda, leeches calcium from the bones. You can read more about how that works here
There’s the possibility of becoming pre-diabetic or full blown diabetic (eventually) because of the white processed bread types of foods which tend to have a much higher glycemic index than do less processed and whole grain breads (and chips and crackers and egg roll coatings etc.)
The whole diet is way too high in fat and preservatives and could lead to weight gain, heart disease and possibly open them up to several types of cancer down the line.
And this diet is way to high in sodium, which can lead to high blood pressure and heart disease.
If you or your friend are looking to change or improve this diet, The Mayo Clinic has a lot of useful information about how to avoid disease through diet, with meal planning tips and lists of bad, good and better food options. Here is a section that deals with avoiding diabetes. This diet is very similar to the diets that help a person to avoid Heart Disease
The American Cancer Society is another good reference for a diet to help prevent cancer
The American Heart Association also has a lot of great information on eating a healthy diet to decrease your risk of Heart Disease
You will notice that all of these diets and tips are very similar and explain what to eat and what to avoid.