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RECRUITING

NCT07888257

LIfestyle MEtabotype Study B (LIME-B)

Sponsor: German Institute of Human Nutrition

View on ClinicalTrials.gov

Summary

Glycemic responses vary significantly among individuals, even when consuming identical foods or meals, but the factors predicting individual glucose responses to food intake remain poorly investigated. The aim of the LIfestyle MEtabotype (LIME) study is to identify lifestyle-related and mechanistic factors which predict individual postprandial glucose fluctuations in individuals with different glycemic status (prediabetes, type 2 diabetes \[T2D\] and absence of prediabetes or T2D), using comprehensive lifestyle characterization and metabolic, molecular and neurocognitive phenotyping. As part of this phenotyping, the LIME study also investigates the role of ketone bodies. Individuals with insulin resistance, prediabetes or T2D often show impaired cerebral glucose utilization. Ketone bodies, such as β-hydroxybutyrate (βHB) may serve as an alternative energy source for the brain. However, how exogenous βHB affects neurocognitive processes and decision-making in individuals with different glycemic status remains poorly understood. This record describes module B of the LIME study. Module B investigates the effects of a single dose of exogenous βHB, compared with a carbohydrate-based placebo drink, on brain structure and function, decision-making behavior and physiological and metabolic responses. Module A comprises a comprehensive lifestyle and metabolic characterization of the same participants and is registered separately as an observational study (NCT07868601). Data from both modules will be integrated in joint analyses.

Key Details

Gender

All

Age Range

40 Years - 75 Years

Study Type

INTERVENTIONAL

Enrollment

300

Start Date

2026-10-26

Completion Date

2031-12-31

Last Updated

2026-10-28

Healthy Volunteers

Yes

Conditions

Nutritional and Metabolic Diseases Prediabetes Type 2 Diabetes

Interventions

DIETARY_SUPPLEMENT

βHB drink (ketone ester)

Single oral dose of a βHB ester (0.3 g/kg body weight), consumed fasted during one of the two visits of module B

DIETARY_SUPPLEMENT

Carbohydrate drink

Single oral dose of an equicaloric and taste-matched dextrose drink.

Inclusion Criteria: * Overweight or obese (BMI 25-40 kg/m²) * Good knowledge of German * Completion of the LIME screening visit; participants who do not take part in the further assessments of module A \[NCT07868601\] may still participate in module B Participants are classified into three groups based on the screening visit: * Group A (without Prediabetes or Type 2 Diabetes) Criteria: HbA1c \<5.7% and fasting plasma glucose \< 100 mg/dl * Group B (Prediabetes) Criteria: HbA1c 5.7-6.4%, or fasting plasma glucose 100-125 mg/dL * Group C (Type 2 Diabetes) Criteria: HbA1c ≥6.5%, fasting plasma glucose ≥ 126 mg/dl, or existing T2D diagnosis by physician, or T2D diagnosis based on an available result from standardized 75 g oral glucose tolerance test Exclusion Criteria: * Weight changes of more than 5% in the last 3 months * Night shift work * Travel across more than one time zone in the last month before and during study participation * Intensive regular physical activity of more than 2 hours per day * Current pregnancy or breastfeeding * Severe renal, liver or heart disease * Existing or past hematological malignancies, other malignant tumors, unless successfully treated more than 12 months before study start * Severe neurological or psychiatric disorders * Daily alcohol consumption of more than 20 grams or more than 150 grams per week * Use of illicit or legal drugs one week prior to study start and during study participation * Known systemic infections * Type 1 diabetes and rare forms of diabetes * Diabetes treatment with insulin or sulfonylureas or diabetes medication in the absence of manifest type 2 diabetes * Unstable thyroid dysfunction * Blood coagulation disorders or anticoagulation therapy that cannot be interrupted * Medications affecting nutrient absorption * Medications with immunosuppressants or steroids (oral or parenteral) * Current eating disorders, functional or structural digestive disorders or bariatric surgery * Food allergies or intolerances to ingredients of the test meals * Intermittent fasting or calorie-restricted diet four weeks prior to the start of the study or during the study * Ketogenic diet or ketogenic supplements four weeks prior to or during module B * Left-handedness * Severe claustrophobia * Electrical implants or non-removable metallic implants * Concurrent participation in another intervention study * Assessment by the study physician based on medical concerns precluding study participation

Locations (2)

Freie Universität Berlin, Center for Cognitive Neuroscience Berlin (CCNB)

Berlin, Germany

German Institute of Human Nutrition

Nuthetal, Germany