Height and weight were only measured in 2005, 2007, and 2008. The original design called for anthropometry every 2 years. However, child malnutrition became a presidential priority with the election of Alan Garcia and there was an expansion of the survey in 2008 to be able to produce departmental-level estimates with greater precision.

The 2004-2008 design called for a different one-fifth subset of the 2000 survey for each continuous survey year, adjusting for changes in cluster size by increasing or decreasing the cluster take and adjusting the final weights for each year for response rates. Thus the weights are combinable over survey years and are not normalized. Normalization does not change the relative weights; however, it does not allow combining years and can't be reversed unless the normalization factor is known.
For 2008, there was a large supplemental sample added from a different sampling frame and weights were calculated to take that into account. Survey years can still be combined with 2008.