title: Effect of macronutrient intake during the second trimester on glucose metabolism later in pregnancy.
abstract: BACKGROUND
  Dietary intake is known to influence glucose metabolism, but there is little consensus on the optimal distribution of macronutrient intakes during pregnancy to prevent gestational diabetes (GDM).
  
  
  OBJECTIVE
  We aimed to investigate whether macronutrient intake distribution during the second trimester of pregnancy was associated with glucose metabolism later in pregnancy.
  
  
  METHODS
  Women with singleton pregnancies and without preexisting type 1 or type 2 diabetes were included. Participants underwent a 3-h oral-glucose-tolerance test at 30 wk (95% CI: 25, 33 wk) gestation and were asked to recall their second-trimester dietary intake by using a validated food-frequency questionnaire.
  
  
  RESULTS
  Of the 205 participants, 47 (22.9%) had a diagnosis of GDM. A higher intake of saturated fat (β ± SEE: 0.059 ± 0.021; P = 0.005) and trans fat (0.381 ± 0.145; P = 0.009) as a percentage of energy and of added sugar (0.017 ± 0.007; P = 0.02) and a lower intake of vegetable and fruit fiber (-0.026 ± 0.012; P = 0.03) were individually associated with increased fasting glucose after multiple adjustment. In participants with a family history of type 2 diabetes, a higher vegetable and fruit fiber intake was associated with reduced insulin resistance (-0.100 ± 0.029; P = 0.0008) and increased insulin sensitivity (0.029 ± 0.012; P = 0.01), after similar adjustment. An increased risk (OR per 1-SD change) of GDM was associated with lower carbohydrate (0.60; 95% CI: 0.40, 0.90) and higher total fat (1.61; 95% CI: 1.06, 2.44) intakes as a percentage of energy, after similar adjustment.
  
  
  CONCLUSIONS
  Macronutrient intake during the second trimester of pregnancy was associated with a risk of abnormal glucose metabolism later in pregnancy. This finding supports the need for continued work to determine optimal prenatal nutritional strategies to prevent GDM. This trial is registered at clinicaltrials.gov as NCT01405547.
authors.affiliation: Department of Nutritional Sciences, Mount Sinai Hospital, Toronto, Canada.
authors.forename: Sylvia H
authors.initials: SH
authors.lastname: Ley
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Hanley
authors.forename: Ravi
authors.initials: R
authors.lastname: Retnakaran
authors.forename: Mathew
authors.initials: M
authors.lastname: Sermer
authors.forename: Bernard
authors.initials: B
authors.lastname: Zinman
authors.forename: Deborah L
authors.initials: DL
authors.lastname: O'Connor
mesh_terms: D000328:Adult; D000886:Anthropometry; D016009:Chi-Square Distribution; D016640:Diabetes, Gestational / Q000209:etiology*; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000378:metabolism; D004041:Dietary Fats / Q000008:administration & dosage / Q000378:metabolism; D004043:Dietary Fiber / Q000008:administration & dosage / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D006801:Humans; D039382:Maternal Nutritional Physiological Phenomena / Q000502:physiology*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second / Q000378:metabolism*; D011795:Surveys and Questionnaires
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004043:Dietary Fiber; D005947:Glucose