CALIBER Phase 1: A Pilot Study in Normal-weight and Overweight Adults.
- Conditions
- Cardiometabolic Risk
- Interventions
- Other: Low-carbohydrate, high-fatOther: High-carbohydrate, moderate-fat
- Registration Number
- NCT03257085
- Lead Sponsor
- Liverpool John Moores University
- Brief Summary
Pilot study to compare the impact of following a low-carbohydrate, high-fat diet versus following a high-carbohydrates, moderate-fat diet (UK dietary guidelines) on cardiometabolic risk markers and associated behaviours in a normal-weight and overweight adult population.
- Detailed Description
Cardiometabolic diseases (CMD), such as type 2 diabetes and cardiovascular disease (CVD), are globally amongst the highest contributors to morbidity and mortality with high (cost) implications to the overall economy and health care systems. A number of risk markers have been associated with CMDs, including blood serum markers, low levels of lean mass and high levels of body fat, including increased waist circumference. Dietary factors and nutritional status have long been linked with specific markers of cardiometabolic (CM) risk. The quantity and quality of dietary carbohydrates has been associated with increased serum triglycerides levels, increased body fat mass, increased waist circumference and visceral fat around the organs in particular. They also seem to increase food cravings. Whilst official dietary guidelines in the UK and elsewhere still recommend a high carbohydrate and low fat diet as standard, these recommendations have increasingly been challenged. Evidence has been mounting that very-low carbohydrate (ketogenic) and low carbohydrate diets can ameliorate CM risk factors, especially when a personalised rather than a one-size-fits-all approach is being taken. Response to carbohydrate load and adherence to dietary interventions can vary widely dependent on individual substrate and energy metabolism and insulin-resistant status.
The majority of dietary interventions with ketogenic and low-carbohydrate diets has focused on weight loss as the primary outcome in overweight and obese individuals. However, in recent years evidence has been mounting that the location and quality of adipose tissue (AT) play a more important role in manifestation of CM risk than quantity of AT alone. Detrimental health behaviours, such as low-quality diet and low levels of physical activity seem to be important contributors to this.
Further studies can provide vital insights into the links between diet, location-specific adipose tissue, CM risk factors and health-related behaviours.
Therefore this 8-weeks randomised pilot study will investigate the impact of either following a low-carbohydrate, high-fat diet versus following a high-carbohydrates, moderate-fat diet (UK dietary guidelines) on cardiometabolic risk markers and associated behaviours in a normal-weight and overweight adult population aged 19 - 64 at potential risk of CMD.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 15
Not provided
Not provided
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Low-carbohydrate, high-fat Low-carbohydrate, high-fat Participants adhering to low-carbohydrate, high-fat diet for 8 weeks. High-carbohydrate, moderate fat High-carbohydrate, moderate-fat Participants following high-carbohydrate, moderate-fat diet for 8 weeks.
- Primary Outcome Measures
Name Time Method Body composition - Bioelectrical impedance 8 weeks Lean mass, fat mass and adipose tissue location and distribution
Tumor necrosis factor alpha and Interleukin 6 8 weeks Measured in μg/mL
Serum lipid profile 8 weeks Total cholesterol, HDL-C, LDL-C, non-HDL cholesterol, small-dense LDL-C and triglycerides measured in mmol/L
Blood glucose 8 weeks Measured in mmol/L
Inflammatory markers, such as CRP 8 weeks Measured in mg/L
Adiponectin 8 weeks Measured in μg/mL
Body composition - Anthropometrics 8 weeks Waist, hip, neck, thigh and calf circumference measured in cm
Systolic and diastolic blood pressure 8 weeks Measured in mmHg
Fibroblast growth factor 21 (FGF21). 8 weeks Measured in pg/mL
- Secondary Outcome Measures
Name Time Method Food cravings 8 weeks Measured via self-reported questionnaire
Cognition 8 weeks Assessed via self-reported questionnaire
Adherence to fibre recommendations 8 weeks Measured via structured questionnaires
Impact on physical activity patterns 8 weeks Assessed via accelerometry
Clinical traditional and emerging markers of dietary intake 8 weeks Fibroblast growth factor 21 and serum metabolites
Satiety 8 weeks Assessed via serum leptin levels (ng/mL)
Adherence to dietary guidelines 8 weeks Measured via diet quality score assessment
Adherence to assigned diet 8 weeks Measured via 4-day food diaries
Adherence to low-carbohydrate diet 8 weeks Measured via blood ketones (mmol/L)
Experience with either low-carbohydrate, high-fat or high-carbohydrate, moderate-fat diet 8 weeks Assessed via semi-structured interview
Adherence to taking dietary supplement for low-carbohydrate, high-fat group 8 weeks Measured via counting of number of multi-vitamin and mineral supplements consumed
Trial Locations
- Locations (1)
Liverpool John Moores University
🇬🇧Liverpool, Merseyside, United Kingdom