Can a smartphone app help people with obesity lose weight?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age 18 years or older * Body mass index (BMI) ≥ 30 * BMI 27-30 in combination with at least one of the following: 1. Has received a diagnosis of obesity from another healthcare provider. 2. Has a comorbidity (according to the defined diagnosis list under the heading Comorbidities below). 3. Has central obesity, defined as waist circumference \> 80 cm for women or \> 94 cm for men. 4. Kostindex score of 4 or lower - eligible for treatment due to increased risk of rapid future weight gain. Dietitian-led intervention may significantly impact weight development in this group. * Ability to read and understand Swedish * Does not currently use, and does not plan to initiate the use of, appetite-suppressing medication * Not pregnant * Patients with BMI \> 40, As long as there is no contraindication for treatment, treatment is offered. A dietitian may deny the patient the Eatit program if the dietitian assesses that the need for care is too great, and that Eatit's treatment cannot meet the patient's needs. Comorbidities: * Cardiovascular disease This is a large group of diagnoses, e.g. previous myocardial infarction or stroke, angina pectoris, heart failure, etc. * Hypertension * Elevated blood pressure, above 130/85 mmHg or ongoing treatment for previously diagnosed hypertension * Hyperlipidemia * Triglyceride levels ≥ 1.7 mmol/L or on treatment for elevated triglycerides, or LDL \> 3.0 mmol/L at low risk, or on treatment for high cholesterol, or reduced HDL-C \<40 mg/dL for men, \<50 mg/dL for women, or on treatment for HDL-C * Obstructive sleep apnea * Type 1 diabetes * Type 2 diabetes * Prediabetes (fasting glucose ≥ 6.1 or HbA1c \> 42 without a diabetes diagnosis) * Fatty liver * Polycystic ovary syndrome, PCOS * Osteoarthritis in the lower body (e.g. hip, knee, or foot) Exclusion Criteria: * BMI: Patients with BMI \< 27 are excluded from treatment. * Medical conditions: Patients with conditions where weight loss or weight gain may worsen the disease are excluded. For example: cancer or chronic obstructive pulmonary disease, COPD. * Multimorbidity: Individuals with extensive comorbidities may have complex healthcare needs requiring more comprehensive medical support than Eatit can provide. * Untreated depression may hinder participation in the program and should be managed with medical or psychological support. * Untreated or ongoing eating disorder (bulimia nervosa, binge eating disorder, anorexia, atypical anorexia, ARFID) should be treated in a specialized eating disorder unit. * Severe psychiatric illness (such as psychosis or schizophrenia) without ongoing support. * Ongoing substance abuse (alcohol, narcotics, or medication) is a contraindication for participation and requires specialized addiction care. * Suicidal behavior or self-harm in the past six months. Acute mental illness requires immediate and specialized interventions. * Requires individual assessment. Certain conditions require individual evaluation as they may negatively affect treatment outcomes. This means that the treating dietitians should ask follow-up questions to ensure that participation in the program is feasible. * Symptoms of binge eating not meeting criteria for binge eating disorder: Ensure that the person is willing to work with the program, not skip meals, and will inform you if the binge eating worsens. * Depression under psychiatric care: Ask follow-up questions about what support the person is receiving and his or her current mental state. * Bipolar disorder: Ask follow-up questions about what support the person is receiving and his or her current mental state. * Exhaustion syndrome/stress: Ask follow-up questions to determine whether treatment is feasible at this time or if the patient needs to manage the stress in other ways first. * Neuropsychiatric disorders: To benefit from the program, sufficient concentration ability and capacity for structure/planning in daily life are required. In case of a neuropsychiatric diagnosis, follow-up questions should be asked about whether the person believes that he or she can manage texts and tasks that take approximately 2-3 hours per week. * High degree of psychiatric comorbidity has in some studies been shown to be a complicating factor, and this should also be considered at the start of treatment. Ask follow-up questions about what support the person is receiving and his or her current mental state. * Severe sleep problems: Sleep deprivation may lead to increased appetite and reduced cognitive capacity, making it difficult to engage with treatment. Ask follow-up questions about possible undiagnosed sleep apnea or potential need for other care to address the sleep problems.