Research

Hormonal

Obesity is associated with a blunted increase in muscle sympathetic nerve activity (MSNA) in response to oral glucose ingestion, despite higher plasma insulin levels, which may contribute to reduced thermic effect of food.

In obesity, the body's ability to increase energy expenditure (via sympathetic nervous system activation) in response to eating is impaired. This blunted response, despite high insulin levels, likely contributes to a lower thermic effect of food, making weight management more difficult. This is a physiological feature of insulin resistance, not just a behavioral issue.

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In conclusion, obesity is associated with a higher fasting sympathetic neural outflow to muscle but a blunted increase in response to an oral glucose load despite a larger increase in plasma insulin levels. This blunted response may represent another feature of the obesity/insulin resistance syndrome.
Maximilian Spraul et al. · Diabetes · 1994

Why this rating

Direct measurement of MSNA via microneurography is the gold standard for sympathetic activity, though the sample size is moderate (31 subjects).

Source

Muscle Sympathetic Nerve Activity in Response to Glucose Ingestion: Impact of Plasma Insulin and Body Fat

Maximilian Spraul et al. · Diabetes · 1994

DOI 10.2337/diab.43.2.191

cross_sectional · n=31Cited 68×
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DOI resolved against Crossref · corpus check 2026-06-10

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