The Effect of Protein-enriched Diet on Body Composition and Appetite

Obesity is a major problem worldwide and current dietary interventions are not proving to be enough to cease the increase in levels of obesity and its detrimental side effects, such as nonalcoholic fatty liver disease (NAFLD).

Existing data suggests that adjustments in the macronutrient composition of the diet, more specifically the protein content, may have beneficial effects on body composition and an antiobesegenic effect on appetite. This may be important in terms of controlling body weight and reducing the amount of fatty tissue within our bodies and organs, and therefore preventing obesity and its health related side effects.

The investigators will perform a study to investigate whether a high protein low energy diet compared to a normal protein low energy diet, in overweight adults can modify appetite and aid loss of weight and fat mass. Subjects will receive either a high protein low energy diet (1.34g protein/kg body weight) or a normal protein low energy diet (0.8g protein/kg body weight) in the form of 2 meal replacements and one conventional meal per day with 2 snacks for 12 weeks.

HYPOTHESIS In overweight subjects with the metabolic syndrome, a 12 week dietary intervention with a high protein low energy diet will lead to a reduced appetite, body weight and fat mass, more specifically to a greater fall in levels of fat in the liver and pancreas than a low energy normal protein diet.


Eligibility Criteria:
Inclusion Criteria:

* Overweight and obese people as classified by BMI 27-35kg/ m2 (inclusive)
* A Finnish Diabetes Risk Score (FINDRISC) \>8 \[22\]
* Waist circumference measurement of ≥102cm in males or ≥88cm in females
* Assessed as appropriate for inclusion, based on a prestudy screening (see section 3.4)
* Willingness and ability to give written informed consent and willingness and ability to understand, to participate and to comply with the study requirements

Exclusion Criteria:

* Claustrophobia
* Pacemaker, metal implant, clips, implanted device, shrapnel or bullets, metal in eyes that precludes magnetic resonance imaging
* Treatment with any medication that might affect the study outcome (e.g., medication that is affecting appetite regulation and/or blood flow)
* Current pregnancy or breast feeding
* Delivery within the last year
* Bariatric surgery
* History of any disease with unknown outcome
* Significant intercurrent disease or history of clinically significant disease of any type, in particular liver, kidney, or heart disease, any form of diabetes mellitus or psychiatric illness (including Depression as defined by BDIII score above 28)
* History of cancer, excluding skin cancer
* History of severe or multiple allergies, severe adverse drug reaction or leucopenia
* Smokers
* Regular drinkers of more than three units of alcohol daily (1 unit = 300 ml beer, 1 glass wine, 1 measure spirit)
* Subjects who have had a fluctuation of body weight \>5% in the 3 months prior to entering into the study
* History of, or current evidence of, abuse of alcohol or any drug substance, licit or illicit
* Regular intake of overthecounter (OTC) medication (other than the occasional paracetamol/aspirin)
* Poor compliers or subjects unlikely to attend
* Blood donation within the 12 week period before the initial study dose