Sweets
Sweets and biscuits mean a sweet reward and a small joy. Being given them as a gift hints at goodwill and praise coming your way, and sharing them out is read as a good dream of building goodwill. Eating them in secret marks that you need a small comfort for yourself right now. That said, old dream lore also read too much sweetness as leaning too far toward pleasure at hand, so read it as a modest joy rather than expecting any great gain. It has nothing to do with actual snacking.
Traditional dream lore treated sugar as pleasure at hand: read favourably, but never inflated. Sweets are not eaten to fill a stomach; they are picked up when the mouth is bored.
Readings by Situation
Being given sweets as a gift
A hint of goodwill and praise coming your way. Old lore read being given food as recognition. Something small but pleasant is about to happen.
Sharing sweets out
A good dream of building goodwill. Giving in a dream is generally read well, so the care you put in now is understood to come back later.
Eating them in secret
It marks a need for a small comfort. That you ate it in hiding is the point: you are not letting yourself rest or enjoy anything openly. If guilt lingered, you are doing in secret something you are perfectly entitled to do in the open.
Sweets so sugary you tire of them
The near pleasure has taken more weight than it should. It is no ill omen, but it signals a look back at whether something has been left undone.
A sweets dream has nothing to do with real snacking or with your health, and it is no reason at all to spend more than you planned.