Purpose A systematical literature review evaluating the effect of dietary counseling in treating weight loss and improving energy intake in patients with advanced cancer with different stages of cachexia. Principal results Five publications were retrieved, of which three were randomized. Two out of five studies showed less weight loss with dietary counseling (+1% weight gain vs. −1.5% weight loss, p = 0.03, 1.4 kg vs. −2 kg, p < 0.05), two presented positive effect on energy intake (92% of total caloric need vs. 73%, p < 0.01, 1865 ± 317 kcal vs. 1556 ± 497 kcal, ns). Conclusion Dietary counseling can effect energy intake and body weight, however, apparent heterogeneity between studies is present. Based on these results there is not enough proof of evidence that dietary counseling given to patients with cancer is beneficial for improving weight or energy balance in the different cachexia stages. Nutrition is an essential part of cachexia treatment as it is not considered possible to increase or stabilize weight if nutritional needs are not met.