Each point on the 5-point scale represents an increase or decrease depending on direction of 20 to 30 percent in body fat above or below ideal. The Body Conditioning chart is a helpful tool for pet owners to increase awareness that their pet may be seriously underweight or overweight. Many serious health conditions can develop as a result of un-managed weight; we strongly advise a veterinary exam and discussing with your vet an appropriate weight management program tailored to your pet's needs. Weight management in cats must be done carefully, if weight reduction is too rapid, conditions such as fatty liver disease or diabetes may occur, in which aggressive medical treatment is necessary.
The following chart is only intended to be a guide. If you suspect your pet does not fall into the "ideal" range, make an appointment with your vet for an examination, evaluation and assessment for a potential weight management protocol.
You can check out some case studies done in the UK in regards to weight control at Purina.com
The information above was gathered from Petsafe and Cathelp-online websites.