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

Imperial College London39 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Enrollment

Conditions

Overweight

Interventions

High Protein, low calorie meal replacementDIETARY_SUPPLEMENT

The high protein group will have meal replacements with added protein powder (to achieve 1.34g protein/kg body weight) and the control group will have standard meal replacements (0.8g protein/kg body weight). Meal replacements have been used in hundreds of previous human studies and are generally not found to be linked to any serious adverse effects.

Eligibility

Sex: ALLMin age: 25 YearsMax age: 70 YearsHealthy volunteers:

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

Change in Lipid Content of the Liver (Intrahepatocellular Lipid)

Changes in body weight and body composition, more specifically visceral, muscle, liver and pancreas fat content will be measured using magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). Individual's data will be compared at baseline and at 12 weeks of following the diet and also to that of the participants given normal protein low energy diets. This data may therefore support our hypothesis that high protein intakes may help to aid weight loss and reduce fat mass and would therefore be a viable option in the treatment of obesity.

Time frame: Change from Baseline at 12 weeks

Secondary Outcomes

Change in Appetite Regulation, Measured by VAS and Food Intake.

It has also been suggested that highprotein diets are more beneficial in the regulation of appetite. We therefore aim to measure any changes in appetite whilst on a highprotein lowenergy diet compared to a normalprotein lowenergy diet. Changes in appetite will be measured using validated questionnaires assessing subjects feeling of hunger, pleasantness and volume able to eat as well as fullness. This data may support our hypothesis that highprotein intakes may alter appetite regulation and therefore be a useful in the treatment of obesity.

Time frame: Baseline and 12 weeks