Metabolic rate - not only for the body as a whole but also for each cell?

When I studied physiology many decades ago, I learnt about the metabolic rate in the human body.

I do not know if there has been any investigation of whether each cell also has a metabolic rate.

My intuition is that each cell does have its own metabolic rate, and that this slows with age.

This metabolic rate for any group of cells can be helped to keep at the right speed through normal stimulation (exercise) and rest.

What does not help is infections and/ or excess sugar or too little sugar or other nourishment.

Distortions in the metabolic rate of any cell or group of cells is at least partly responsible for obesity, cancer, and so on.

Presumably, there is a symbiotic relationship between the metabolic rate of each cell and the amount of nutrition it receives - in other words, the metabolic rate should determine how much nutrition it absorbs even if it is surrounded with too much nutrition. However, constantly having too much nutrition may eventually disturb the metabolic rate.

Perhaps that is one reason why regular or occasional fasting improves health for normal people?