Interventions that target excessive gestational weight gain (EGWG) with nutrition and exercise behavior change struggle with low program adherence. The investigators recently examined adherence in a randomized controlled trial to a previously established lifestyle program called the Nutrition and Exercise Lifestyle Intervention Program (NELIP) and found that those individuals with high adherence to the program were more likely to prevent EGWG. Perhaps offering participants a choice to intervention strategies may improve adherence. The current research question is: What impact does participant choice have on adherence to the introduction of nutrition and exercise components during 3 intervention strategies offered to pregnant individuals compared to no choice and does choice maintain pregnancy health outcomes? The strategies are: Group A - introducing both the nutrition and exercise components simultaneous at baseline (12-18 weeks of pregnancy) that is followed to delivery (NELIP); Group B - introducing the nutrition component first and then at 25 weeks adding the exercise component; or Group C - starting with the exercise component first, followed with introducing the nutrition component at 25 weeks. Both Groups B and C follow the full NELIP from 25 weeks to delivery (final intervention measures will occur at 34-36 weeks gestation). Follow-up will occur at birth (6-18 hours), 2, 6 and 12 months post delivery.

Investigators are using a pseudo randomized yoked design and will include two groups: choice of intervention strategy or no-choice. If the individual is randomized to no choice, then the next person would get a choice and the no choice person would be assigned to the group yoked (matched) to the person with a choice. Participants assigned to the choice group will choose one of three intervention strategies provided; either Group A (receiving both nutrition and exercise simultaneously), B (starting with nutrition and receiving exercise sequentially followed by nutrition starting at 25 weeks) or C (starting with nutrition first and then introducing exercise sequentially at 25 weeks). All groups will follow the full NELIP until delivery. Participants in the no-choice group will be yoked (matched) to a participant in the choice group and receive the strategy that their yoked counterparts chose.

Nutrition component of NELIP: This component is a modified gestational diabetic meal plan that has four general goals tailored to the participant: (1) to achieve approximately 2000 kcal of energy per day. The determination of the amount of kcal consumed per day will consider the participant's intake from the dietary assessment. There also must not be a restriction of calories that exceeds 30% of their total energy intake; (2) participants will consume approximately 200-250g/day of carbohydrates, accounting for approximately 40-55% of total energy intake. Carbohydrate intake will be distributed throughout three meals and four snacks daily. The nutritionist will educate participants about the importance of complex and low-glycemic index carbohydrates through the one-on-one session; (3) fat and protein intake will be approximately 30% and 20-30% of total energy intake, respectively; (4) achieve appropriate micronutrient and fluid intake for pregnancy. This will be monitored by a weekly 24 hour food intake record.

Exercise component of NELIP: This is a walking program that comprises of 1 weekly supervised session on a treadmill or outside and participants will be recommended to walk 2 to 3 additional times per week. The walking program will start at 25 minutes per session, 3 to 4 times weekly, and increase by 2 minutes per week until 40 minutes and then maintained until delivery. This will be monitored by a wrist monitoring device. The primary outcome is adherence measured weekly using a published adherence protocol using a point system. Secondary outcomes are participant satisfaction to the program and health outcomes: weekly weight gain, calculated EGWG, and pregnancy outcomes (birth weight length, infant anthropometrics, APGAR scores and delivery complications). At 2, 6 and 12 months of age the maternal-infant dyad will return to the lab and infant morphometric measurements recorded from birth will be repeated.

Inclusion Criteria:

• between 12 to 18 weeks of pregnancy
• a singleton fetus
• medically screened with the Get Active Questionnaire for Pregnancy to determine eligibility for participation in the exercise component

Exclusion Criteria:

• inability to walk
• serious medical problems
• high blood pressure
• uncontrolled chest pain
• uncontrolled symptomatic lung disease
• diabetes before pregnancy
• a history of recreational substance use disorder
• any contraindication to exercise
• enrolled in another clinical trial.

All gender identities will be accepted as these individuals must be pregnant.

deidentified data may be shared after publication

After completion of the study and after publication

Access with be determined by the principal investigator once the reasons for data acquisition are given

data analysis will be analysed blinded to group