Adding a bit of fat to a carb-heavy meal does blunt the glucose spike that follows, but overdoing it can backfire: leaning on protein and fiber alongside it works better than piling on large amounts of fat.

noli's read

The nuance in this post, a warning against overusing her own hack, is consistent with a more fine-grained literature than the hack itself. A meta-analysis (European Journal of Clinical Nutrition, 2019) confirms that each 10% of calories swapped from carbohydrate to fat in a meal modestly lowers postprandial glucose and insulin, but also raises postprandial triglycerides, a trade-off, not a pure win. More striking: a study in healthy postmenopausal women (British Journal of Nutrition) found that a breakfast rich in saturated fat reduced insulin sensitivity at the next meal hours later, a "carry-over" effect documented specifically for saturated fat (less so for monounsaturated fat). That directly validates the post's warning: overdoing fat on carbs can "backfire", not just at the immediate next meal but with a delayed effect. The recommendation to lean on protein and fiber instead is also supported: a review (PMC, Impact of Nutrient Type and Sequence) shows protein preloads blunt a later meal's glucose peak more effectively and more cleanly than a fat preload.

the sources

1. 1Shukla AP, Andono J, Touhamy SH, et al. 2017
2. 2Shukla AP, Iliescu RG, Thomas CE, Aronne LJ 2015
3. 3Shishehbor F, Mansoori A, Shirani F 2017
4. 4Buffey AJ et al. 2022
5. 5Bellini A et al. 2023