Inclusion Criteria:

• * Pregnant women
• * ≥ 8 and ≤ 15 weeks gestation at time of screening. This range of gestational age is chosen to: a) reduce chances of false pregnancy or miscarriage under 8 weeks gestation and b) recruit women in the 1st trimester for greatest impact of the intervention on gestational weight gain. In the feasibility and initial impact study, the investigators had less than 10% (n=3) miscarriages prior to randomization using these criteria
• * Singleton gestation
• * Any parity (i.e., first-time pregnancy, second pregnancy, etc.)
• * Any race/ethnicity
• * Ages 18-45 years \[based on our pilot data this group comprises more than 85% of the live births in Central Pennsylvania\]
• * Overweight or obese: body mass index (BMI) range 25.0 to 45.0. If BMI is over 40, consultation with woman's health care provider will be made to determine eligibility and ensure she does not have any contraindications to physical activity or other concerns with intervention participation.
• * Haven't exceeded 25% or more of their total GWG (based on BMI and IOM guidelines) from pre-pregnancy to date of enrollment.
• * Participant has physician consent to confirm subject participation
• * Able to read, understand, and speak English
• * Residing in and around State College, PA, Penn State Hershey Medical Center, Hershey, PA, and Geisinger, Danville, PA for the duration of the study
• * Access to a computer/phone
• * Willingness to attend onsite visits to complete study materials and intervention sessions. If randomized to the intervention, willingness to receive intervention content electronically (e.g., email, Facetime, Zoom), at home (e.g., Zoom sessions delivered synchronous and asynchronous) or if requested by the participant, on-site at Penn State University Park or Hershey campuses.
• * Not currently smoking
• * No severe allergies/dietary restrictions/eating disorders that may preclude study participation
• * No diagnosed insomnia
• * No absolute contraindications to exercise in pregnancy and relative contraindications with provider consent (see below)

Exclusion Criteria:

• * Not pregnant women
• * Men (unable to become pregnant)
• * Multiple gestation
• * \< 8 weeks gestation or \> 15 weeks gestation at time of pre-intervention assessment
• * Outside of the age range of 18-45 years
• * Outside of the BMI range of 25.0-45.0
• * Exceeded 25% of their total GWG (based on BMI and IOM guidelines) from pre-pregnancy to date of enrollment
• * Not able to read and/or understand English
• * Not residing in or around the target recruitment sites in Central Pennsylvania
• * Unable to commute to study locations for assessments and/or not able to access materials by computer or phone (even with data plan assistance if necessary)
• * Currently smoking
• * Pre-existing diabetes
• * Diagnosed insomnia (women will self-report their insomnia)
• * Pre-existing eating disorders. Women will self-report their eating disorder diagnosis history and the study team will check their electronic health record data/confirm with physician.
• * Severe allergies and dietary restrictions that may preclude study participation.
• * Contraindications to aerobic exercise in pregnancy:
• Absolute:
• Haemodynamically significant heart disease Restrictive lung disease Incompetent cervix/cerclage Multiple gestation at risk for premature labor Persistent second or third trimester bleeding Placenta praevia after 26 weeks gestation Premature labor during the current pregnancy Ruptured membranes Pregnancy induced hypertension
• Relative (if permission is not given by provider):
• Severe anemia Unevaluated maternal cardiac arrhythmia Chronic bronchitis Poorly controlled type I diabetes Extreme morbid obesity Extreme underweight (body mass index less than 12.0) History of extremely sedentary lifestyle Intrauterine growth restriction in current pregnancy Poorly controlled hypertension/pre-eclampsia Orthopedic limitations Poorly controlled seizure disorder Poorly controlled thyroid disease Heavy smoker