Standard antiviral treatment consists of weekly injections with Peginterferon-α in combination with ribavirin. This treatment may lead to significant weight loss (7% within 24 weeks on average), with decreased quality of life. In this study the investigators will examine in 50 patients whether nutritional advise and support can prevent weight loss during antiviral therapy.

Standard antiviral treatment consists of weekly injections with Peginterferon-α in combination with ribavirin. This therapy, however, leads to weight loss of approximately 7% in the first 24 weeks of therapy possibly related to impaired postprandial gastric emptying. Such rapid weight loss is a marker of deterioration of the nutritional status with increased risk of complications and reduced immunological barrier function. Deterioration of the nutritional status also exacerbates side effects of the antiviral treatment like fatigue and depression. As a result, the quality of life of these patients may decrease. In the current controlled, prospective, multicenter, study we primarily aim to compare the effects of preventative versus on demand nutritional advice in combination with nutritional support on reduction of weight loss in patients receiving standard antiviral therapy with PEG-interferon in combination with ribavirin. We will randomize patients for the preventative intervention with dietary consultation combined with dietary supplementation of a daily snack or the on demand dietary support group (only dietary follow up, no dietary advice or snack, standard care). In the on demand group, patients will be referred to the dietitian in case of weight loss of ≥ 5% or a BMI < 20 during antiviral therapy. Assuming that 60% reduction of weight loss during the first 24 weeks of treatment is clinically relevant, 2 x 25 patients need to be included (α=0.05, β=0.2: power=0.8 and a drop-out rate of 15%). Primary aim is to assess whether the intervention can decrease the amount of weight loss during therapy.

Inclusion Criteria:

• Diagnosis of hepatitis C
• Indication for antiviral therapy
• Age > 18 years
• Good understanding of Dutch or English language
• Informed consent

Exclusion Criteria:

• Co-infection with hepatitis B and/or HIV
• Significant non hepatic diseases
• Significant previous surgery of the gastro-intestinal tract
• Hepatocellular carcinoma or other current malignant disease
• BMI < 20