The use of insects recently emerged as an alternative source of high-quality animal protein for both animal and human food supplementation use with lower environmental impact. Recent evidence indicates that an insect-based diet provides an improved animal production mass gain and showed benefits for human health. The present study evaluated the dietary supplementation effect of the Tenebrio molitor fermented and wholemeal flour on the metabolism of diet-induced obese mice. Male Swiss mice were divided into 4 groups treated for 4 weeks as follows: standard diet, high-fat diet, high-fat diet + wholemeal flour and high-fat diet + fermented flour. The 15% wholemeal or fermented flour were added to the diet. Several parameters such as food/energy intake, body weight, adipose tissue weight, biochemical levels, adipose tissue histology and mRNA expression were evaluated. The main results showed that the inclusion of wholemeal and fermented T. molitor flour induced body weight loss, adiposity reduction and specific changes in biochemical and histological parameters. In addition, was observed significant changes in lipogenic gene expression. The insect flour negatively modulated the expression of the SREBP1α, CEBP1α, FAS, ACC gene and positively modulated PGC1α. In conclusion, the main findings showed the T. molitor flour potential use to improve dyslipidaemia and adiposity with beneficial effects on metabolic diseases.