Continuous glucose monitors reveal variable glucose responses to the same meals

Perceived obviousness vs. usefulness of the finding

• Many commenters say variable glucose responses to identical meals are “expected” or “obvious,” especially to people living with diabetes.
• Others stress that even “unsurprising” results matter: science often quantifies what common sense predicts and provides reference data for future, more controlled studies.
• Some criticize the short duration (14 days, two repeats per meal) and untracked factors (snacks, water) as limiting how much we can infer.

Sources of variability in glucose response

• Repeatedly mentioned factors: hydration, physical activity before/after meals, stress, sleep quality and slow‑wave sleep, illness/inflammation, hormones, temperature, and time of day.
• Meal context matters: order of foods (fiber/protein vs carbs first), presence of fat, size and timing of snacks, “excitement” or emotional arousal about food.
• Gut microbiome, glycogen status, gastric emptying, and even chewing are suggested contributors.
• Some point out that 80% “within‑person” variation may partly be measurement error.

Experiences of people with diabetes

• Multiple type 1 diabetics report that identical meals with identical insulin doses routinely produce very different glucose outcomes, which is demoralizing.
• Parents of children with T1D echo that variability is constant and exhausting.
• Type 2 diabetics describe late or prolonged spikes (e.g., after rice or sweets) and confusion about diagnoses vs. their CGM data. Others note A1c–glucose mismatches due to red blood cell lifespan differences.

Continuous glucose monitors: power and limitations

• CGMs are widely praised as life‑changing: real‑time safety (especially at night), better understanding of how foods and activities affect them, and enabling closed‑loop systems.
• Several note significant CGM imperfections: lag vs. blood glucose, sensor placement issues, calibration problems, and occasional large discrepancies with lab or finger‑stick measurements.
• Some worry the article’s framing might discourage CGM use; others argue variability makes continuous monitoring more, not less, valuable.

Personalized nutrition, products, and EBM

• Services that promise diet recommendations from short CGM runs (e.g., two‑week logging) are met with skepticism; commenters doubt reliable extrapolation given so many uncontrolled variables.
• Debate over evidence‑based medicine vs. “common sense”: some argue EBM underestimates individual variation; others counter that N‑of‑1 trials and personalization are already core EBM concepts.