Potatoes have plenty of vitamin C and good amounts of fiber and potassium. However, followers of this fad diet will have some nutritional problems. One medium plain potato has only 170 calories mostly as carbohydrate, but lacks in protein and fats. It contains only 5 grams of protein. In terms of total protein, a follower of this diet would have to eat about 11 potatoes a day, since an adult male needs about 56 grams of protein a day. However, potatoes are not high quality proteins – they are considered incomplete proteins since they lack enough of the nine amino acids needed for protein synthesis.
The type of starch in potatoes is digested more rapidly, according to the Harvard School of Public Health. The rate of digestion combined with the quantity of starch in a potato result in a high glycemic index rating. A baked Russet potato (150 grams) has an average score of 111. This score is higher than pure glucose, which means the baked potato creates a fast and large spike in blood sugar that can lead to insulin resistance, weight gain and diabetes.
Needless to say, the “Spud Fit” diet is not a good idea.