Still, it is very difficult to fulfill the energy, protein, calcium and iron requirements, especially for children (who need these nutrients for physical and mental development), teens and young adults with a decent exercise routine and women who are pregnant or nursing. It is not at all recommended for them to follow such a diet.

This type of diet is most suited for adults, carrying an unhealthy lipid profile and those wanting to lose weight (though a good amount of beans needs to be included in the fruitarian diet to bring about a healthy weight loss).

A person whose diet is 75 percent fruit is likely to have more health issues than a person on a diet consisting of 50 percent fruit. It is a risk for diabetics to adopt this diet as fruits have high sugar content. There are risks of serious nutritional deficiencies, including vitamin B, calcium, iron, zinc, omega-3 and omega-6, amino acids, and protein. There is also the risk of unhealthy weight loss (muscle loss over the fat loss). It can be highly devastating for a pregnant or lactating mother to follow such a diet. Over a period of time, people on a fruitarian diet are also prone to develop health problems, including emaciation, constant hunger, weakness, and fatigue.

There is very little scientific research that supports fruitarianism as a healthy lifestyle, especially over long-term, unless foods such as beans, green vegetables, soy, and whole grains are included in the diet, keeping the fruit intake to a maximum of 50 percent of the total diet.