The purpose of this explorative clinical trial is to study parasite population dynamics, diversity and clearance kinetics of Plasmodium falciparum as well as determination of the molecular mechanisms associated with drug resistance during the early phase of artemether-lumefantrine treatment when the drug intake is either accompanied with or without intake of fatty food. The hypothesis is that intake of fatty food together with artemether-lumefantrine will enhance parasite clearance and thereby decrease the risk of early selection of genetic markers related to drug resistance. The study population is children aged 1-10 years with uncomplicated malaria in Bagamoyo District, Tanzania. Enrolled children will be randomly allocated to either intake of a fatty meal or not together with the study drug. Artemether-lumefantrine will be given twice daily for 3 days in standard doses according to bodyweight. Study participants will be admitted during the study period (3 days)to allow close supervision and detailed blood sampling.

Inclusion Criteria:

• Age 1-10 years
• Presence of asexual P. falciparum parasitaemia of 2000-200 000/μL
• No general danger signs or severe malaria present
• Haemoglobin ≥70 g/L
• History of fever within 24 hours OR axillary temperature ≥ 37.5Cº
• No other cause of fever is detectable
• No severe malnutrition
• Guardian/patient has understood the procedures of the study and willing to participate

Exclusion Criteria:

• Not able to drink or breastfeed
• Vomiting everything
• Recent history of convulsions
• Lethargic or unconscious
• Unable to sit or stand (as appropriate for age)
• History of allergy to test drugs
• History of intake of any drugs other than paracetamol and aspirin within 3 days
• Symptoms/signs of severe malaria