Using field types to override meta defaults
To override the Default meta data with your field type the only addition you need in your code is to pass the entry.id to your craft.sproutSeo.meta tag:

{% do craft.sproutSeo.meta({ 
    id: entry.id,    
    default: 'default',
    title: entry.title,
    description: entry.body|striptags|slice(0, 160)
}) %}


Once you identify the entry.id Sprout SEO will handle the rest, prioritizing any values you have in your field types above any values in your Defaults or Code Overrides.