Researchers in the US have discovered a jab that works with the body's immune system to combat the effects of a slow metabolism.
The metabolic rate is the speed at which your body burns energy, with a low rate linked to increased weight gain.
According to the Journal of Animal Science and Biotechnology, mice injected with the vaccine shed ten per cent of their body weight in four days.
The jab dupes the immune system into creating antibodies that combat the weight-gain hormone somatostatin - which works by slowing the metabolism.
As the antibodies attack the hormone and counteract its effects, the metabolism speeds up for improved weight loss.
Dr Keith Haffer, lead researcher and spokesman for the US firm Braasch Biotech, said: "This study demonstrates the possibility of treating obesity with vaccination.
"Although further studies are necessary to discover the long term implications of these vaccines, treatment of human obesity with vaccination could provide physicians with a drug and surgical-free option against the weight epidemic."
This solution is not set to hit consumer shelves for between seven and ten years, so getting that bikini body will still need to involve more traditional methods for weight loss.
Obesity is defined as a body mass index (BMI) of more than 30, with a healthy BMI ranging between 18.5 and 24.9.
Figures from the Department of Health show 62.8 per cent of English adults were overweight or obese in 2010, while more than 30 per cent of children aged between two and 15 were also classified as overweight or obese.
Foresight's Tackling Obesities: Future Choices predicts that if current trends continue, 60 per cent of men and 50 per cent of women in Britain will be obese by 2050.
The government recommends following the eatwell plate for a balanced diet, which is comprised of foods from the five main groups.