Food and Water

I have started using the base healing rate (BHR) from Heroic fantasy. It makes a lot of sense that recovery and healing are based on a scale of how many hits you have vs a static number.  Love it!  So, now I am wondering if something similar should be applied to food and water consequences instead of a fixed number.

As it stands right now, failure to eat enough food for day results in 1hp of damage.  A 1st level fighter with 4 HP can last 4 days, but a 11th level fighter with 40 HP can last 40 days.  

Water seems harsher.  Failure to drink enough water for day results in 1d4 damage.  First, this can outright kill a 1st level Mage with 2 HPs. If you assume an average damage of 2 on the roll, a mage at 10th level could last 9 days without water, which is pretty extreme.  More so, a 11th level fighter with 40 HPs could last 20 days without water, which should be impossible. 

My thoughts are to use the Max Result of BHR chart for water penalty and the BHR dice for Food.  

Max HP Water Hits Food Hits
1-3 2* 1d2*
4-9 3* 1d3*
10-16 4 1d4
17-23 6 1d6
24-29 8 1d8
30-36 10 1d10
37-49 12 2d6

Note: Minimum Days survival is 2 Days w/o Water and 5 days w/o Food. If HP drops to below zero before minimum days, assume Player is at 1 HP, but still receives cumulative penalties and cannot heal naturally.   

Thoughts?

If you are trying to compensate for characters with different HP totals, you might just ditch all ties to HP when considering food and water.  Here's an example of paraphrased rules from the Sine Nomine game "Other Dust" for hunger and thirst:

Each day a character gains 1 hunger point and 1 thirst point. If you don't eat or drink, you gain conditions (Hungry, Thirsty, etc) that each apply -2 to d20 rolls and -1 to 2d6 rolls.  You can't be Hungry twice, but you can be both Hungry and Starving.  You must remove all hunger or thirst points to remove those conditions.

Consuming one ration of food removes one point of hunger. You gain no benefit from consuming more than 2 rations per day. When hunger points rise to 5, save or become Hungry. At 15 points, automatically become Hungry and save or become Starving. At 30 points, become Dazed and save or drop dead from hunger. At 45 points, drop dead from hunger. 

Consuming a ration of water removes a point of thirst. With sufficient clean water, you can drink away as much thirst as you've accumulated. When thirst points rise to 2, save or become Thirsty. At 4 points, become both Thirsty and Parched, and save or die of thirst. At 6 points, die of thirst.