Here's my edited config

thresholds = [1.0, 2.0, 3.0, 4.0, 6.0]
benefitsUnparsed = ["attribute,generic.max_health,-1", "attribute,generic.max_health,-1", "attribute,generic.max_health,-1", "attribute,generic.max_health,3", "attribute,generic.max_health,5;attribute,generic.armor_toughness,3"]

When i do this, config seems to have a problem and reports an error.

I can't figure out from the wiki how to set it up to penalize the player for consuming only a few types of food.

The toml file says

Each benefit is a string with the following form: [+/-][type],[registry name],[value] (without the brackets)
A leading plus (or the of a symbol) denotes a benefit, while a minus denotes a detriment.

According to this, should I put a sign of - in front of attribute to create a penalty,
so that it looks like -,attribute,generic.max_health,-1 ?