Research

Energy balance

A very low energy diet (2.3 MJ/day) for 7 weeks followed by gradual reintroduction significantly reduces the severity of moderate to severe obstructive sleep apnoea (AHI) in obese men, with the greatest clinical benefit observed in patients with severe baseline disease.

For obese men with moderate to severe sleep apnoea, a strict liquid very low energy diet (approx 550 kcal/day) for 7 weeks, followed by a 2-week transition to normal eating, can significantly reduce sleep apnoea severity. This approach is particularly effective for those with severe symptoms, potentially allowing them to reduce or stop CPAP use. The key is rapid, significant weight loss, which reduces neck circumference and airway obstruction.

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Treatment with a low energy diet improved obstructive sleep apnoea in obese men, with the greatest effect in patients with severe disease.
Kari Johansson et al. · BMJ · 2009

Why this rating

Randomized controlled trial with low dropout, intention-to-treat analysis, and clear statistical significance (P<0.001).

Source

Effect of a very low energy diet on moderate and severe obstructive sleep apnoea in obese men: a randomised controlled trial

Kari Johansson et al. · BMJ · 2009

DOI 10.1136/bmj.b4609

rct · n=63Cited 287×
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DOI resolved against Crossref · corpus check 2026-06-10

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