“DNA-guided diet advice produces better weight loss than comparable advice without DNA testing.”
DNA-guided diet advice has not been shown to produce more weight loss than equally good advice without a DNA test.
A DNA test is not the missing piece for weight loss. In trials, people lost about the same amount of weight whether or not their diet advice was matched to their genes. Useful personal advice can come from your goals, food preferences, health needs and how your body responds over time.
If you are thinking about buying a DNA diet test, put that money toward an eating plan or support you can stick with instead.
Several randomized trials, including a 609-person year-long trial, found no added weight-loss benefit from matching diets to genes. Confidence is moderate because the results agree, but the trials tested only a few gene panels and some were small, short or lost many people.
DNA-guided diet advice has not been shown to produce more weight loss than equally good advice without a DNA test. Knowing a genetic variant does not identify one ideal diet for a person.
In the DIETFITS trial, 609 adults followed a healthy low-fat or healthy low-carb diet for a year. Their gene pattern did not predict who lost more weight on which diet, and both groups lost about 11 to 13 pounds. In the POINTS trial, people placed on the diet matched to their genes lost about 11.7 pounds in 12 weeks, versus about 10.6 pounds for those on the mismatched diet, a difference too small to rule out chance. In the Food4Me trial across seven European countries, adding gene results to personalized advice did not improve eating habits beyond advice based on a person's diet alone (weight was not the main outcome). A smaller year-long trial in the Philippines also found no added benefit, though only 27 of 52 people stayed to the end.
- Gardner CD, Trepanowski JF, Del Gobbo LC, Hauser ME, Rigdon J, Ioannidis JPA, Desai M, King AC. Effect of Low-Fat vs Low-Carbohydrate Diet on 12-Month Weight Loss in Overweight Adults and the Association With Genotype Pattern or Insulin Secretion: The DIETFITS Randomized Clinical Trial. JAMA. 2018;319(7):667-679. DOI: 10.1001/jama.2018.0245. PMID: 29466592
- Höchsmann C, Yang S, Ordovás JM, Dorling JL, Champagne CM, Apolzan JW, Greenway FL, Cardel MI, Foster GD, Martin CK. The Personalized Nutrition Study (POINTS): evaluation of a genetically informed weight loss approach, a Randomized Clinical Trial. Nature Communications. 2023;14(1):6321. DOI: 10.1038/s41467-023-41969-1. PMID: 37813841
- Celis-Morales C, Livingstone KM, Marsaux CF, et al.; Food4Me Study. Effect of personalized nutrition on health-related behaviour change: evidence from the Food4Me European randomized controlled trial. International Journal of Epidemiology. 2017;46(2):578-588. DOI: 10.1093/ije/dyw186. PMID: 27524815
- Nacis J, Labrador JP, Ronquillo DG, et al. Effect of gene-based vs. standard weight-loss recommendations on anthropometry, lipid and glucose markers, and dietary intake: a randomized controlled trial (the MyGeneMyDiet Study). Genes & Nutrition. 2026;21(1):4. DOI: 10.1186/s12263-026-00794-z. PMID: 41654718