Obesity and its related health problem, like fatty liver disease and type 2 diabetes, are major health problems worldwide and can lead to serious illness and reduced quality of life. Most advice focuses on eating fewer calories and increasing physical activity, but new research suggests that when we eat may also matter. Late meals can disrupt blood sugar control, how the body processes fat, and hormone balance. However, it is not fully understand how meal timing affects people who may be more at-risk. For example new mothers face disrupted sleep, which can lead to eating later in the day. People with fatty liver disease may have eating patterns that unintentionally worsen their condition.

To explore this, the study will include the following groups;

1. First-time mothers in early motherhood, and women who do not have children.
2. People with fatty liver disease along with people of similar age, sex, and weight who do not have the condition.

The aim of the study is to compare meal timing habits between these groups. All participants will complete a 3-day diet diary and a questionnaire about eating habits, sleep, lifestyle, and daily routines. Some participants may opt to complete an optional body composition check using a mobile app. A smaller subset of volunteers will take part in additional assessment, including a fasting blood sample, basic measurements (such as height, weight, and waist size), a body scan to measure fat and muscle. They will also wear a small device to track their blood sugar and another to monitor sleep and activity for 14 days. This study will increase the current understanding on how eating patterns and daily routines differ in these groups, and may help improve future advice on healthy lifestyles.

Inclusion Criteria:

General (applied to all participants)

• Willing and able to give informed consent for participation in the study and perform study assessments
• Access to a smartphone or computer to complete digital questionnaires and dietary logs.

MASLD Cohort

• Age 18-80
• Confirmed self-reported MASLD diagnosis, irrespective of disease stage (cases)
• Control group: Absence of confirmed MASLD diagnosis

Early Motherhood Cohort

• Age 18-50
• Women in early motherhood, defined as up to 12 months of their first successful childbirth delivery at enrolment
• Control group: Women who have never given birth

Exclusion Criteria:

Adult participants may not enter the study if ANY of the following apply:

• Self-reported active disease involving major organ dysfunction (except from Type 2 Diabetes Mellitus and Cardiovascular Disease for MASLD cohort)
• Current smoking, heavy alcohol consumption (AUDIT score greater than 8 will be classified as heavy alcohol consumption), or recreational drug use
• Current use of appetite-suppressant, appetite-stimulants, or weight-modifying pharmacotherapy (e.g., GLP-1 agonists, antidepressants, GIP agonists)
• Recent unintentional rapid weight loss greater than 5% of body weight within the past 2 months, not attributable to recent pregnancy or intentional postpartum weight loss.
• Current shift workers, defined as individuals working regular evening, night, rotating, or irregular schedules that disrupt standard sleep-wake cycles.
• Currently pregnant or >1 year women after childbirth
• Participants who cannot consent for themselves.

Adults with Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) and women in early motherhood, recruited alongside matched control groups, from the NIHR BioResource cohort and community recruitment channels in the Cambridgeshire region, UK. A subset of participants will be recruited through the Institute of Metabolic Science at Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, for optional in-person assessments.