To evaluate the effect of dietary intervention on metabolic risk profile, and on potential simultaneous changes in physiological and cognitive functions and to collect a unique database using state-of-the-art technologies on variables related to the above mentioned areas.

The study is compiled from 4 phases: 1) a pilot study to evaluate performance and feasibility of the measurements and logistics for the BRAVE intervention study (N=10), 2) a pre-screening phase to select volunteers for the intervention study based on metabolite analyses (N=600), 3) the BRAVE intervention study as a controlled non-randomized open-label fixed sequence diet switch trial (N=88)and 4) a non-interventional reference group to estimate the learning effect due to repeated cognitive testing (N=30).

The Brainfood dietary regime is planned optimal for metabolism and cognitive function; having focus on regular meal frequency (breakfast, lunch and afternoon snack) and well-balanced light lunch at work -according to the so-called plate model and optimized recipes- will be provided.

Inclusion criteria

1. Signed written informed consent
2. Age 18-65 years
3. Assumed metabolic risk based on pre-screening assessment of glucose and lipid metabolism related metabolites defined initially as being within the most impaired quartile with reference to available metabolite data-base from a comparable population. If recruitment efficiency requires, having a metabolic profile within the most impaired half instead of a quartile may be applied.
4. Male or female with at least 1/3 of the gender defined predominant among screened participants with assumed metabolic risk
5. Adequate Finnish or English skill to comprehend trial related instructions and questionnaires
6. Chest circumference of 75 to 115 cm (limits included)

Exclusion criteria

1. High probability to travel for more than one working day a week during the trial
2. Expected or planned major changes in lifestyle (diet, level of exercise, significant changes in work) or involved in the R&D of the measuring devices applied in the trial
3. Allergies restricting compliance with control or intervention diet (celiac disease, gluten free diet, stringent FODMAP diet)
4. Nickel allergy
5. History of unstable coronary artery disease (myocardial infarction, coronary artery bypass graft (CABG), percutaneous transluminal coronary angioplasty (PTCA), temporal ischemic attack within the previous 6 months
6. Diagnosed type 1 or type 2 diabetes requiring treatment
7. Inflammatory bowel disease or other intestinal or oesophageal disease requiring medical treatment or likely to have a nutritional affect
8. History of malignant diseases like cancer within five years prior to recruitment
9. Lipid lowering medication (statin, cholestyramine) or medication for obesity (orlistat, or liraglutide) or depression
10. Alcohol abuse (> 4 portion/per day) or recreational drug abuse
11. Pregnancy or planned pregnancy or lactating
12. Suspected low compliance according to the investigator's assessment