Clinic records included serial measurements of height and weight and father’s occupation. On average each person had been measured 11 times between birth and 2 years of age.

Data on socioeconomic position (SEP) in childhood, defined as father’s highest attained occupational status, was extracted from birth, child welfare, and school records.

Data on SEP in adulthood were obtained from Statistics Finland, where information on occupational status, educational attainment, and taxable incomes were available at an individual level at 5-year intervals.

Participants in this follow-up in this clinical study were traced by social security number, which is a unique identifier for every resident of Finland.

Information on weight and height were obtained from postal questionnaires which were sent to the participants at a mean age of 60 years.

Participants' living habits included information on smoking status, alcohol consumption and physical activity.

Date and causes of death were obtained from the Finnish National Death Register.

The clinical assessment comprised extensive phenotypic data, including metabolic data, dietary information as well as other lifestyle data. Psychological factors including personality, depression and anxiety has also been focused on. 

The whole diet was assessed by using a self-administered questionnaire. Depression, anxiety, loss of behavioural/emotional control and psychological well-being, loss of vitality and energy during the four weeks prior to the clinical examination were assessed by questionnaires.

Height, weight, waist circumference and hip circumference were measured. An oral glucose tolerance test was performed.

Blood was collected. A genome-wide association study was performed on the participants.

Diagnoses were extracted from the Finnish Hospital Discharge Register which contained data on all hospitalizations in psychiatric and general hospitals in Finland between 1969 and 2008. Information on psychotropic medication was derived from the Finnish National Social Insurance Institution register.

Personality assessment was done by postal questionnaire and included items on neuroticism, extraversion, openness to experience, agreeableness and conscientiousness.

All participants visited the study clinic after an overnight fast. Weight and height were measured and BMI was calculated. Blood samples included a standard oral glucose tolerance test. Information on medical history, current medication, smoking and leisure-time physical activity were obtained using questionnaires at the clinic. A food-frequency questionnaire was used to collect data on diet, alcohol intake, and total caloric intake.