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OPTIFAST Science

Developed by scientists, widely researched and tested, OPTIFAST is a clinically proven, scientifically designed low calorie diet recommended for the dietary management of weight loss.

The Science Behind OPTIFAST

With so many different diets to choose from and countless stories about weight loss, it’s hard to know if you have selected a safe and effective option. 

One way to know is to make sure your chosen diet has a strong scientific basis, like the OPTIFAST diet plans. 

The OPTIFAST diet plans are clinically proven, nutritionally complete & balanced, and medically endorsed.


Clinically Proven

OPTIFAST products are backed by strong clinical evidence that shows the diet plans can help people achieve sustainable weight loss. There are a variety of OPTIFAST diet plans tailored to meet a wide range of weight loss needs. Our scientists are continually updating the OPTIFAST products and programmes to reflect the latest weight loss science.

Nutritionally Complete & Balanced

OPTIFAST products are based on scientifically designed recipes developed by a team of experts. OPTIFAST brings you nutritionally complete & balanced options proven to help you lose and keep off excess weight.

Our dietitians regularly update OPTIFAST products to reflect the most current thinking on the science of weight loss. Our most recent product line revision increased protein levels, decreased carbohydrates and removed added sugars using high quality ingredients. Our experts work hard to provide the right balance of macro nutrients (proteins, carbohydrates and fats) in every product.

OPTIFAST product can be used as part of a total diet replacement which includes 100% of the recommended daily value for at least 24 vitamins and minerals, ensuring you are getting all the micro nutrients (vitamins and minerals) you need. Nutritionally complete and balanced,Optifast products help you lose weight and maintain good health.

Medically Endorsed

We work closely with the medical community to ensure our OPTIFAST diet plans and products adhere to the highest medical standards:

• The OPTIFAST Programmes are supported by and conducted through many of the world’s leading Medical Institutions and by many advisory boards of experts in the field of obesity. Doctors around the world use an OPTIFAST program to help their patients lose weight safely and effectively,

• Our nutritionists partner with leading clinicians at globally renown universities to push the science of weight loss forward. 

• Our products are developed with strict attention to government health agency guidelines around the world, such as the most recent European Guidelines for Obesity Management in Adults (2015). 

• Our nutrition experts partner with scientific organisations on the forefront of obesity management such as Obesity Medicine, the American Society for Metabolic and Bariatric Surgery, the Obesity Action Coalition and the Obesity Society