title: Changes in Physical Activity Following a Genetic-Based Internet-Delivered Personalized Intervention: Randomized Controlled Trial (Food4Me).
abstract: BACKGROUND
  There is evidence that physical activity (PA) can attenuate the influence of the fat mass- and obesity-associated (FTO) genotype on the risk to develop obesity. However, whether providing personalized information on FTO genotype leads to changes in PA is unknown.
  
  
  OBJECTIVE
  The purpose of this study was to determine if disclosing FTO risk had an impact on change in PA following a 6-month intervention.
  
  
  METHODS
  The single nucleotide polymorphism (SNP) rs9939609 in the FTO gene was genotyped in 1279 participants of the Food4Me study, a four-arm, Web-based randomized controlled trial (RCT) in 7 European countries on the effects of personalized advice on nutrition and PA. PA was measured objectively using a TracmorD accelerometer and was self-reported using the Baecke questionnaire at baseline and 6 months. Differences in baseline PA variables between risk (AA and AT genotypes) and nonrisk (TT genotype) carriers were tested using multiple linear regression. Impact of FTO risk disclosure on PA change at 6 months was assessed among participants with inadequate PA, by including an interaction term in the model: disclosure (yes/no) × FTO risk (yes/no).
  
  
  RESULTS
  At baseline, data on PA were available for 874 and 405 participants with the risk and nonrisk FTO genotypes, respectively. There were no significant differences in objectively measured or self-reported baseline PA between risk and nonrisk carriers. A total of 807 (72.05%) of the participants out of 1120 in the personalized groups were encouraged to increase PA at baseline. Knowledge of FTO risk had no impact on PA in either risk or nonrisk carriers after the 6-month intervention. Attrition was higher in nonrisk participants for whom genotype was disclosed (P=.01) compared with their at-risk counterparts.
  
  
  CONCLUSIONS
  No association between baseline PA and FTO risk genotype was observed. There was no added benefit of disclosing FTO risk on changes in PA in this personalized intervention. Further RCT studies are warranted to confirm whether disclosure of nonrisk genetic test results has adverse effects on engagement in behavior change.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01530139; http://clinicaltrials.gov/show/NCT01530139 (Archived by WebCite at: http://www.webcitation.org/6XII1QwHz).
authors: Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre + (MUMC+), Maastricht, Netherlands. c.marsaux@maastrichtuniversity.nl.
authors: Cyril F M
authors: http://orcid.org/0000-0002-4725-6359
authors: CF
authors: Marsaux
authors: Carlos
authors: http://orcid.org/0000-0003-2612-3917
authors: C
authors: Celis-Morales
authors: Katherine M
authors: http://orcid.org/0000-0002-9682-7541
authors: KM
authors: Livingstone
authors: Rosalind
authors: http://orcid.org/0000-0003-3734-6489
authors: R
authors: Fallaize
authors: Silvia
authors: http://orcid.org/0000-0002-8360-797X
authors: S
authors: Kolossa
authors: Jacqueline
authors: http://orcid.org/0000-0001-8761-6497
authors: J
authors: Hallmann
authors: Rodrigo
authors: http://orcid.org/0000-0001-8054-6553
authors: R
authors: San-Cristobal
authors: Santiago
authors: http://orcid.org/0000-0002-5163-2230
authors: S
authors: Navas-Carretero
authors: Clare B
authors: http://orcid.org/0000-0003-3367-6173
authors: CB
authors: O'Donovan
authors: Clara
authors: http://orcid.org/0000-0001-6323-0012
authors: C
authors: Woolhead
authors: Hannah
authors: http://orcid.org/0000-0001-5944-8027
authors: H
authors: Forster
authors: George
authors: http://orcid.org/0000-0003-3009-6675
authors: G
authors: Moschonis
authors: Christina-Paulina
authors: http://orcid.org/0000-0001-8065-989X
authors: CP
authors: Lambrinou
authors: Agnieszka
authors: http://orcid.org/0000-0003-2189-9249
authors: A
authors: Surwillo
authors: Magdalena
authors: http://orcid.org/0000-0002-1891-7859
authors: M
authors: Godlewska
authors: Jettie
authors: http://orcid.org/0000-0003-2442-4361
authors: J
authors: Hoonhout
authors: Annelies
authors: http://orcid.org/0000-0002-4115-5186
authors: A
authors: Goris
authors: Anna L
authors: http://orcid.org/0000-0003-0368-9336
authors: AL
authors: Macready
authors: Marianne C
authors: http://orcid.org/0000-0002-6651-2434
authors: MC
authors: Walsh
authors: Eileen R
authors: http://orcid.org/0000-0001-9465-052X
authors: ER
authors: Gibney
authors: Lorraine
authors: http://orcid.org/0000-0002-7711-7499
authors: L
authors: Brennan
authors: Yannis
authors: http://orcid.org/0000-0001-6486-114X
authors: Y
authors: Manios
authors: Iwona
authors: http://orcid.org/0000-0002-0483-7778
authors: I
authors: Traczyk
authors: Christian A
authors: http://orcid.org/0000-0002-7216-2784
authors: CA
authors: Drevon
authors: Julie A
authors: http://orcid.org/0000-0001-7633-9455
authors: JA
authors: Lovegrove
authors: J Alfredo
authors: http://orcid.org/0000-0001-5218-6941
authors: JA
authors: Martinez
authors: Hannelore
authors: http://orcid.org/0000-0003-3937-9719
authors: H
authors: Daniel
authors: Michael J
authors: http://orcid.org/0000-0001-5250-361X
authors: MJ
authors: Gibney
authors: John C
authors: http://orcid.org/0000-0003-3406-3002
authors: JC
authors: Mathers
authors: Wim H M
authors: http://orcid.org/0000-0003-0985-0047
authors: WH
authors: Saris
mesh_terms: D000328:Adult; D005260:Female; D005820:Genetic Testing / Q000379:methods*; D005838:Genotype; D006801:Humans; D020407:Internet; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009765:Obesity / Q000235:genetics*; D057285:Precision Medicine; D057566:Self Report; D011795:Surveys and Questionnaires
keywords: FTO; Web based; behavior change; disclosure; genetic testing; personalized intervention; physical activity; randomized controlled trial