Hi..thanks for your query
There is a possibility that you have developed Lentigenes or Freckles.It might be familial in origin; this condition is aggravated by UV light sources, sun maximally. .Please wear a sunscreen with broad spectrum like Cetaphil
UVA UVB defense during the day time.It is important to use umbrella , wear protective clothing and reapply the sunscreen 4-6 hourly.
Diet will not be able to help much here, however please continue having the healthy diet plan
.There are several other possibilities in this case as well, and they can be best discussed with a dermatologist
observing you.You should visit a dermatologist for Full body skin examination twice yearly to review the spots and to note any changes .
Hope this is helpful..take care.