A new study suggests personality can affect a successful weight loss program.

Researchers in Japan followed 101 obese patients for the findings. In addition to psychological profiles, all participants received counseling, nutrition and exercise therapy for six months.

The results, published in the journal BioPsychoSocial Medicine, suggest that individuals with high levels of self-orientation and optimism were less likely to lose weight than those who needed counseling to improve their self-awareness.

However, an optimistic personality was deemed positive for maintaining results and lifestyle changes learned during the program.

While enhancing patients personalities through counseling was found to be important for weight loss, the scientists say it’s just a part of the overall equation. "The weight loss should be attributed not simply to the intervention of the clinical psychologists but to the total effect of the intervention of a holistic medical care team," said the study’s authors.

Nutritional supplements containing chromium, ephedra, hoodia, bitter orange and green tea extract have all been said to improve weight loss results.