Why eating fewer carbs for 3 days made blood sugar spike higher
Short-term low carbohydrate/high-fat diet intake increases postprandial plasma glucose and glucagon-like peptide-1 levels during an oral glucose tolerance test in healthy men
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
When healthy young men ate mostly fat and very few carbs for just 3 days, their blood sugar went up more after drinking sugar water, even though their body made more of a hormone called GLP-1 that usually helps control blood sugar.
Surprising Findings
GLP-1 increased while blood sugar also increased — a paradoxical combo.
GLP-1 is known to stimulate insulin and lower glucose. Seeing it rise alongside higher blood sugar suggests the insulin response is broken, not the signal.
Practical Takeaways
If you're testing low-carb or keto, monitor your post-meal blood sugar — especially after carbs — even if you feel fine.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
When healthy young men ate mostly fat and very few carbs for just 3 days, their blood sugar went up more after drinking sugar water, even though their body made more of a hormone called GLP-1 that usually helps control blood sugar.
Surprising Findings
GLP-1 increased while blood sugar also increased — a paradoxical combo.
GLP-1 is known to stimulate insulin and lower glucose. Seeing it rise alongside higher blood sugar suggests the insulin response is broken, not the signal.
Practical Takeaways
If you're testing low-carb or keto, monitor your post-meal blood sugar — especially after carbs — even if you feel fine.
Publication
Journal
European Journal of Clinical Nutrition
Year
2012
Authors
Shigeharu Numao, Shigeharu Numao, H. Kawano, Naoya Endo, Yosuke Yamada, Masayuki Konishi, M. Takahashi, S. Sakamoto
Related Content
Claims (10)
Reduction in dietary carbohydrate intake improves postprandial glycemic control and lowers circulating triglyceride levels in humans.
Eating very low-carb, high-fat food for just three days makes blood sugar spike higher after drinking a sugary drink, compared to eating a normal diet.
After eating a high-fat, low-carb diet for three days, the pancreas releases less insulin right after you drink sugar — even though blood sugar goes up.
Even though the body released more of a sugar-controlling hormone after eating fat for three days, blood sugar still went higher—meaning the hormone wasn’t strong enough to fix the problem.
After eating a high-fat, low-carb diet for three days, the body releases more of a gut hormone called GLP-1 when you drink sugar water — even though blood sugar goes higher.