There is little doubt about the dangers of overeating but growing research on more than half a dozen animals groups including mice, flies and worms have shown eating fewer calories can extend an animals life by up to 50%.
The latest tests have been carried out on two grey mouse lemurs (Microcebus murinus, lemurid primate). One group had a normal diet for nine years and the other was fed a similar balanced diet that had 30 per cent fewer calories. The lifespan of the calorie-restricted lemur increased by nearly 50 per cent (from 6.4 to 9.6 years, median survival), and its motor capacities remained healthy its whole life, while its brains resembled that of a younger animal.
They reported that the calorie restricted animals had reduced aging-associated diseases and preserved loss of brain white matter in several brain regions. However, caloric restriction accelerated loss of grey matter throughout much of the cerebrum without affecting cognitive performances. What this means they are not sure.
The health benefits of chronic caloric restriction resulting in lifespan extension are well established in many short-lived species. However, the effects in humans and other primates remain unknown and controversial. Beneficial effects of caloric restriction on age-related diseases have also been reported for long-lived species, including rhesus monkeys (Macaca mulatta). However, increased survival was only reported in one study.
At the very least this suggests that you should not over eat and as I always say make sure you eat nutrient dense foods. 50% of the diseases we now suffer are a result of what we eat.
Caloric restriction increases lifespan but affects brain integrity in grey mouse lemur primates. April 2018