PRE-Pregnancy Weight Loss And the Reducing Effect on CHILDhood Overweight - Copenhagen (PREPARE CHILD)

Maternal inclusion Criteria: Maternal pre-pregnancy BMI 27.0-44.9 kg/m^2 Maternal age range 18-38 years Connected to Hvidovre Hospital as place of birth Not pregnant or breastfeeding Paternal Inclusion Criteria: Paternal pre-pregnancy BMI 18.5-44.9 kg/m^2 Paternal age range 18-55 years Parental Inclusion Criteria: Couples (male and female) Planning pregnancy within 1 year Provided voluntary informed consent Danish or English speaking Intention to permit the planned offspring to participate in the follow-up study Able to store biological samples from the offspring at home in the freezer in a box given by the study personnel Parental Exclusion Criteria: Diabetes mellitus (Type 1 or 2) Previous or present eating disorder Allergy towards ingredients in the very low calorie diet products Severe heart, liver or kidney disease Conception by in vitro fertilization ≥4 consecutive spontaneous pregnancy loss (female) Having tried to conceive or prior time to pregnancy of more than 12 months Any medical condition or concomitant medication as judged by the medical responsible Adherence to vegan diets or other diets interfering with the dietary guidelines in the study Participation in other clinical trial Engagement in elite sports or similar strenuous exercise ≥5 h/week Blood donation or transfusion within the past month before baseline Blood donation during the study Inability or unwillingness to follow the study protocol and instructions given by the study personnel Pregnancy registered at baseline visit (urinary analysis with dipstick) A detailed description of the exclusion criteria is given below: Medical conditions as known by the participant: Diabetes mellitus (type 1 and 2) History or diagnosis of eating disorder (e.g. restrained eating, disinhibition, emotional eating) Any significant medical condition as assessed by the investigator (e.g. dysregulated thyroid disease or reproductive diseases) Any significant psychiatric disorder (i.e. schizophrenia, bipolar disease or depression) as assessed by the investigator Severe chronic heart, liver and kidney disease Polycystic ovary syndrome with irregular cycle Amenorrhea Severely reduced semen quality incl. azoospermia Medication: - Current use of medication or use within the previous three months with a potential to affect body weight or pregnancy as judged by the investigator (e.g. systemic corticoids) Personal/other: Having tried to conceive or prior time to pregnancy of more than 12 months Weight changes ± 5% three months prior to inclusion Severe food allergies, food intolerances or dislike expected to interfere with the study, including allergy towards ingredients in the VLCD products Engagement in elite sports or similar strenuous exercise ≥5 h/week Blood donation or transfusion within the past month before baseline Planned blood donation for other purpose than this study during participation Alcohol abuse, as judged by the investigator, within the previous 12 months Drug abuse, as judged by the investigator, within the previous 12 months Psychological or behavioral problems which, in the judgement of the investigator, would lead to difficulty in complying with the study protocol Participation in other clinical trials within the past three months or intention to do so during the study, which are judged by the investigator to affect the present study Unable to consume the interventional product for religious reasons, swallowing disorders, other physiological reasons or any other reasons for not being able to follow the recommended diet Inability or unwillingness to give written informed consent or communicate with study personnel Inability or unwillingness to follow the study protocol and instructions given by the study personnel Illiteracy or inadequate understanding of Danish or English language. Any other condition that judged by the investigator may interfere with the adherence to the study protocol