The study, carried out by the Children's Hospital of Philadelphia, provided new insight into body mass index (BMI) levels, with researchers uncovering links to lipid-related diseases including type-2 diabetes.
A meta-analysis of 46 studies was conducted by 200 scientists across nearly 109,000 adults, spanning four ethnic groups.
Researchers leading the study used the CardioChip - a gene array containing probes for 50,000 genetic variants across 2,100 genes relevant to cardiovascular and metabolic functions.
Data on around 51,000 people of European ancestry (EA) was looked at to discover initial gene signals, with replica studies carried out on a further 27,000 EA subjects and 14,000 EA individuals.
Analyses of data from an estimated 12,500 African Americans, 2,600 Hispanics and 1,100 East Asians was also used to strengthen the team's findings.
"Previous studies have shown that genetics plays an important role in obesity, and this study expands our knowledge of BMI genetics," said Dr Yiran Guo, who holds a Davis Foundation Postdoctoral Fellowship in Eating Disorders.
Three novel signs from the genes TOMM40-APOE-APOC1, SREBF2 and NTRK2 were associated with adult BMI - all of which had been previously linked to important disorders like Alzheimer's disease and type-2 diabetes.
NTRK2 is particularly noteworthy because it codes for a receptor of the BDNF protein which is related to BMI and is linked with anorexia.
Dr Guo noted how the dataset from previous studies enabled researchers to "enhance our understanding of BMI genetics, as well as the interplay between genetic variants and metabolic disorders such as obesity".
The team was also able to test for conditional associations within genes, leading them to discover two new genes BNDF and MC4R - both of which harbour independent signals for BMI.
"While the individual effects of each gene may be small, they provide fundamental clues to the biology of adult obesity," Dr Guo concluded.
Learning more about the possible genetic links to obesity could help combat the nation's growing waistline, with 26 per cent of adults in England now classified as obese.