CALIBER Phase 1: A Pilot Study in Normal-weight and Overweight Adults.
Study Details
Study Description
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.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
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.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Low-carbohydrate, high-fat Participants adhering to low-carbohydrate, high-fat diet for 8 weeks. |
Other: Low-carbohydrate, high-fat
Participants following low-carbohydrate, high-fat diet for 8 weeks.
Other Names:
|
| Experimental: High-carbohydrate, moderate fat Participants following high-carbohydrate, moderate-fat diet for 8 weeks. |
Other: High-carbohydrate, moderate-fat
Participants following high-carbohydrate, moderate-fat diet (UK dietary guidelines) for 8 weeks.
Other Names:
|
Outcome Measures
Primary Outcome Measures
- 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
- Systolic and diastolic blood pressure [8 weeks]
Measured in mmHg
- Inflammatory markers, such as CRP [8 weeks]
Measured in mg/L
- Adiponectin [8 weeks]
Measured in μg/mL
- Fibroblast growth factor 21 (FGF21). [8 weeks]
Measured in pg/mL
- Tumor necrosis factor alpha and Interleukin 6 [8 weeks]
Measured in μg/mL
- Body composition - Bioelectrical impedance [8 weeks]
Lean mass, fat mass and adipose tissue location and distribution
- Body composition - Anthropometrics [8 weeks]
Waist, hip, neck, thigh and calf circumference measured in cm
Secondary Outcome Measures
- Clinical traditional and emerging markers of dietary intake [8 weeks]
Fibroblast growth factor 21 and serum metabolites
- Food cravings [8 weeks]
Measured via self-reported questionnaire
- Satiety [8 weeks]
Assessed via serum leptin levels (ng/mL)
- Cognition [8 weeks]
Assessed via self-reported questionnaire
- Impact on physical activity patterns [8 weeks]
Assessed via accelerometry
- Adherence to assigned diet [8 weeks]
Measured via 4-day food diaries
- Adherence to dietary guidelines [8 weeks]
Measured via diet quality score assessment
- Adherence to low-carbohydrate diet [8 weeks]
Measured via blood ketones (mmol/L)
- Adherence to fibre recommendations [8 weeks]
Measured via structured questionnaires
- 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
- Experience with either low-carbohydrate, high-fat or high-carbohydrate, moderate-fat diet [8 weeks]
Assessed via semi-structured interview
Eligibility Criteria
Criteria
Inclusion Criteria cohort 1:
-
BMI 18.5 - 29.9kg/m2
-
Aged 19 - 64
-
White-Caucasian
-
Score of ≥4 from a combination of risk markers, including
-
Fasting glucose concentration >5.5mmol/L = 3 points
-
Waist >102cm or 40 inches = 2 points (males)
-
Waist >94 cm or 37 inches = 1 point (males)
-
Waist >88cm or 34inches = 2 points (females)
-
Waist >80 cm or 31 inches = 1 point (females)
-
Systolic blood pressure>130mmHg = 1 point
-
Diastolic BP >85mmHg = 1 point
-
HDL cholesterol concentration <1.0mmol/L = 2 points
-
Serum triglyceride concentration >1.3mmol/L = 1 point.
Exclusion Criteria cohort 1:
-
Smoker
-
Vegetarian or vegan
-
Suffering from food allergies or intolerances
-
Drinking alcohol above recommended UK government guidelines
-
Previous diagnosis of CM disease
-
Taking lipid-lowering medication
-
Taking blood pressure-lowering medication
-
Taking blood glucose-lowering medication
-
Taking dietary supplements
-
Suffering from an eating disorder
-
Current or previous renal impairment
Inclusion Criteria cohort 2:
-
BMI 18.5 - 29.9kg/m2
-
Aged 19 - 64
-
White-Caucasian
Exclusion Criteria cohort 2:
-
Smoker
-
Vegetarian or vegan
-
Suffering from food allergies or intolerances
-
Drinking alcohol above recommended UK government guidelines
-
Previous diagnosis of CM disease
-
Taking lipid-lowering medication
-
Taking blood pressure-lowering medication
-
Taking blood glucose-lowering medication
-
Taking dietary supplements
-
Suffering from an eating disorder
-
Current or previous renal impairment
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Liverpool John Moores University | Liverpool | Merseyside | United Kingdom | L17 6BD |
Sponsors and Collaborators
- Liverpool John Moores University
- Liverpool Hope University
Investigators
- Study Chair: Ian G Davies, PhD, Liverpool John Moores University
Study Documents (Full-Text)
None provided.More Information
Additional Information:
- Brehm, B. et al. (2003) A randomized trial comparing a very low carbohydrate diet and a calorie-restricted low fat diet on body weight and cardiovascular risk factors in healthy women J Clin Endocrinol Metab 88(4), 1617
- Buyken, A., Goletzke, J., Joslowski, G., Felbick, A., Cheng, G., Herder, C. and Brand-Miller, J. (2014) Association between carbohydrate quality and inflammatory markers: systematic review of observational and interventional studies Am J Clin Nutr 99(4),
- De Larochellière, E. et al. (2014) Visceral/epicardial adiposity in nonobese and apparently healthy young adults: association with the cardiometabolic profile Ath
- Fischer, K., Pick, J., Moewes, D. and Nöthlings, U. (2015) Qualitative aspects of diet affecting visceral and subcutaneous abdominal adipose tissue: a systematic review of observational and controlled intervention studies Nutr Rev 73(4), 191-215
- Gadgil, M., Appel, L., Yeung, E., Anderson, C., Sacks, F. and Miller, E. (2013) The effects of carbohydrate, unsaturated fat, and protein intake on measures of insulin sensitivity: results from the OmniHeart trial Diabetes Care 36 (5), 1132-1137
- Gardner, C. (2012) Tailoring dietary approaches for weight loss Int J Obes Suppl 2(Suppl 1), S11-S15
- Hu, T. and Bazzano, L. (2014) The low-carbohydrate diet and cardiovascular risk factors: evidence from epidemiologic studies Nutr Metab Cardiovasc Dis 24(4), 337-343
- Hu, T., Yao, L., Reynolds, K., Niu, T., Li, S., Whelton, P., He, J., Steffen, L. and Bazzano, L. (2016) Adherence to low-carbohydrate and low-fat diets in relation to weight loss and cardiovascular risk factors Obes Sci Pract, 2(1), 24-3
- Ko, B., Park, K., Shin, S., Zaichenko, L., Davis, C., Crowell, J., Joung, H. and Mantzoros, C (2016) Diet quality and diet patterns in relation to circulating cardiometabolic biomarkers Clin Nutr. 35(2), 484-90
- Lee, M., Wu, Y. and Fried, S. (2013) Adipose tissue heterogeneity: implication of depot differences in adipose tissue for obesity complications Mol Aspects Med 34 (1), 1-11
- Lennerz, B., Alsop, D., Holsen, L., Stern, E., Rojas, R., Ebbeling, C., Goldstein, J.and Ludwig, D. (2013) Effects of dietary glycemic index on brain regions related to reward and craving in men Am J Clin Nutr 98(3), 641-647
- Allam-Ndoul, B., Guénard, F., Garneau, V., Cormier, H., Barbier, O., Pérusse, L., et al. (2016) Association between Metabolite Profiles, Metabolic Syndrome and Obesity Status. Nutrients 8(6)
- Lin, Z., Gong, Q., Wu, C., Yu, J., Lu, T., Pan, X., Lin, S. and Li, X. (2012) 'Dynamic change of serum FGF21 levels in response to glucose challenge in human J Clin Endocrinol Metab, 97(7), E1224-1228.
Publications
None provided.- CALIBER