Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting the upper and lower motor neurons, which can lead to death from respiratory failure within 3-5 years after the onset of this disease. Nowadays, no drug can effectively slow down the progression of this disease. High-calorie therapy, an emerging complementary alternative treatment, has been reported in studies to prolong the survival time of patients, prevent muscle atrophy and provide a better prognosis. However, no systematic review and meta-analysis were performed to summarize the evidence of this therapy. This meta-analysis comprehensively evaluates the effectiveness and safety of high-calorie therapy for treating ALS.

We searched the electronic databases from inception to 1 April 2023: PubMed, Embase, Web of Science, Cochrane Library, Scopus, Ovid/Medline, and ProQuest. Randomized controlled trials (RCTs) that met the inclusion criteria were performed by meta-analysis. All statistical analyses were performed in STATA software.

A total of six eligible RCTs were included in this meta-analysis, involving 370 ALS patients. The meta-analyses showed that high-calorie therapy had superiority in improving body weight (SMD = 1, 95% CI 0.36, 1.65) and BMI (SMD = 0.83, 95% CI 0.02, 1.63). With respect to safety, there was no difference between the high-calorie therapy and the control group regarding the number of adverse events (RR = 3.61, 95% CI 0.08, 162.49). However, ALSFRS-R scores (SMD = 0.34, 95% CI - 0.4, 1.08), survival rate (RR = 1.23, 95% CI 0.98, 1.55), and lipid profile (LDL: SMD = 0.21, 95% CI - 0.33, 0.75; HDL: SMD = 0.17, 95% CI - 0.37, 0.71; TC: SMD = 0.21, 95% CI - 0.33, 0.75), CRP (SMD = 0.85, 95% CI - 1.37, 3.06) showed no significant difference compared to the control groups.

High-calorie therapy is effective in gaining weight and BMI with few side effects. However, no significant superiority was detected in ALSFRS-R scores, survival time, lipid profile, and CRP indicator. The overall quality of the included studies is high, and the results have some credibility, but future corroboration by high-quality RCTs is also expected.