In the below video, Malcolm Green discusses the causes of obesity. This talk was done at Think Parrots in 2018, but the information behind it can be applied to all species of birds.
It is highly likely that obesity is the most common cause of premature death in pet and caged birds, yet it is the easiest of problems to prevent. Over many generations bird keepers have tried to match the food we feed with the diets of wild birds. This is fine in theory but our cage birds get far less exercise than their wild cousins. We are constantly being told that to lose weight we need to eat less and exercise more, the same applies to our birds.
Unfortunately limiting our birds' food intake doesn't work all that well...
Small birds risk starving to death and any bird on a restricted diet risks amino acid deficiency. Interestingly birds will eat until their protein (amino acid) requirements are met. With diets that are low in protein but high in energy (often containing high levels of oils, starches and sugars) birds will continue eating to get enough protein but, in the process, they get too much excess energy that they store as fat. Boosting the protein level of the diet means they eat less food to satisfy their protein needs and so don't get fat.
There are two ways to achieve this. The most obvious is to feed foods with high protein levels relative to their energy content. Actually this is quite hard to do as only lean meat, egg white or peas and beans are likely to satisfy this requirement. Alternatively a very high protein supplement like ProBoost SuperMax can be used and, surprisingly, this is probably the cheaper option. However there is an even more efficient and cheaper approach.
This involves helping the bird to use all the protein it currently eats. With traditional diets the bird can only use about 60% of the protein it eats. By adding adequate quantities of the limiting amino acids lysine and methionine to the diet we can enable the bird to use virtually all the protein it eats.
Better than that, most overweight birds that are properly supplemented like this will actually reduce their total food intake and lose weight completely safely. They will never starve to death because, as soon as they need more energy, they will feel hungry again.
However for a few birds this approach doesn't work. These birds are those that have become addicted to fats, sugars or salt - again the same foods that can con us humans into eating too much. So the birds must be offered a balanced diet, not one made up of just sunflower seed, chips or sweet treats! For these birds we have designed Fussy Feeder Essentials and Fussy Eater Banquet*.
Obesity risks the same diseases in birds as it does in humans - liver and kidney failure, heart and circulatory disease and diabetes are probably the most common. Birds with liver disease normally lose weight before the major symptoms show so it can sometimes be difficult to convince their owners that obesity was the original issue.
Reducing the stress on the liver and kidneys
None of the organs that obesity damages are very good at repairing themselves which is why they are the prime diseases we humans now treat with transplant surgery.
This method is actually better for birds with organ damage than the simple boosting of protein levels.
* Currently only available for UK Mail order.