Ketone ester drink versus carbohydrate drink in prediabetes, type 2 diabetes and healthy adults
Tests a ketone drink against a carbohydrate drink on brain function and decisions.
Plain-language title generated from the registry record
Registry title: LIfestyle MEtabotype Study B (LIME-B)
Key facts
- Where
- Berlin and Nuthetal, GermanySee the 2 sites
Could this be for you?
Answer for yourself. This is not a decision: only the study team can say whether you can take part.
- Are you between 40 and 75 years old?
Source: NCT07888257, who can take part
Where in Germany
- Freie Universität Berlin, Center for Cognitive Neuroscience Berlin (CCNB)Berlin, GermanyTaking people
- German Institute of Human NutritionNuthetal, GermanyTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- German Institute of Human Nutrition
- Trial code
- NCT07888257
- Record updated
- 28 October 2026
- Original description
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.Read full original descriptionShow less
LIfestyle MEtabotype Study B (LIME-B)
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.
Inclusion: 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: Travel across more than one time zone in the last month before and during study participation; Existing or past hematological malignancies, other malignant tumors, unless successfully treated more than 12 months before study start; Use of illicit or legal drugs one week prior to study start and during study participation; Diabetes treatment with insulin or sulfonylureas or diabetes medication in the absence of manifest type 2 diabetes; Medications affecting nutrient absorption; Medications with immunosuppressants or steroids (oral or parenteral); 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; Electrical implants or non-removable metallic implants; Concurrent participation in another intervention study; Severe renal, liver or heart disease; Severe neurological or psychiatric disorders; Known systemic infections; Type 1 diabetes and rare forms of diabetes; Blood coagulation disorders or anticoagulation therapy that cannot be interrupted; Current eating disorders, functional or structural digestive disorders or bariatric surgery; Food allergies or intolerances to ingredients of the test meals; Weight changes of more than 5% in the last 3 months; Night shift work; Intensive regular physical activity of more than 2 hours per day; Current pregnancy or breastfeeding; Daily alcohol consumption of more than 20 grams or more than 150 grams per week; Unstable thyroid dysfunction; Left-handedness; Severe claustrophobia; Assessment by the study physician based on medical concerns precluding study participation.