FTO: Appetite, Body Weight Risk, and What You Can Still Change

Episode Notes

Most people have never heard of FTO, but once you understand what it is, a lot of the body weight conversation starts making more sense. This episode breaks down how researchers first found FTO, why it became such an important part of obesity genetics, what the early numbers actually showed, why the first diabetes signal changed once body mass index was factored in, how this gene region may connect to appetite and food cues, where GLP 1 overlaps with that biology, and what training, movement, sleep, stress, and food quality can still change in real life.

Timestamps

0:00 Opening

0:53 What FTO actually is

1:48 How researchers first found it

2:40 What GWAS means

3:24 What BMI means

4:13 Why the early diabetes signal changed

5:18 What FTO may be influencing in the body

6:32 Appetite, hunger, and food cue biology

8:00 Ghrelin and why hunger may feel louder

9:19 Fat cell programming, IRX3, and IRX5

10:42 Where GLP 1 overlaps with the conversation

11:58 Why FTO does not cleanly predict GLP 1 response

12:43 What lifestyle can still change

13:22 Physical activity and the FTO risk signal

14:14 Weight training, sleep, stress, and food structure

15:22 Practical takeaways

16:02 Closing

Key Terms

FTO

Fat mass and obesity associated gene. A gene region strongly associated with body weight risk in common genetics research.

GWAS

Genome wide association study. A method used to scan the genome for common variants linked to traits or disease across large populations.

BMI

Body mass index. A rough height to weight measure often used in large population studies.

rs9939609

One of the most studied FTO variants in obesity research. In many studies, the A allele is associated with higher average body weight risk.

Ghrelin

A hormone involved in hunger signaling and appetite regulation.

GLP 1

Glucagon like peptide 1. A hormone involved in satiety, appetite regulation, and gastric emptying. GLP 1 receptor agonists act on that pathway.

IRX3 and IRX5

Genes implicated in mechanistic studies of how obesity associated variation in the FTO region may influence fat cell programming.

References

Frayling TM, Timpson NJ, Weedon MN, et al. A common variant in the FTO gene is associated with body mass index and predisposes to childhood and adult obesity. Science. 2007;316(5826):889 to 894.

Scuteri A, Sanna S, Chen WM, et al. Genome wide association scan shows genetic variants in the FTO gene are associated with obesity related traits. PLoS Genetics. 2007;3(7):e115.

Karra E, O’Daly OG, Choudhury AI, et al. A link between FTO, ghrelin, and impaired brain food cue responsivity. Journal of Clinical Investigation. 2013;123(8):3539 to 3551.

Kilpeläinen TO, Qi L, Brage S, et al. Physical activity attenuates the influence of FTO variants on obesity risk: a meta analysis of 218,166 adults and 19,268 children. PLoS Medicine. 2011;8(11):e1001116.

Claussnitzer M, Dankel SN, Kim KH, et al. FTO obesity variant circuitry and adipocyte browning in humans. New England Journal of Medicine. 2015;373(10):895 to 907.

Zheng Z, et al. Glucagon like peptide 1 receptor: mechanisms and advances. Frontiers in Endocrinology. 2024.

German J, et al. Association between plausible genetic factors and weight loss from GLP1 RA and bariatric surgery. Nature Medicine. 2025;31(7):2269 to 2276.

Disclaimer

*The Unlocked Podcast is educational content, not medical advice. For personal medical decisions, consult a qualified professional.