How much does the cat eat? (An interactive visualization)
The quick answer to this fascinating question is that the cat ate a daily average of 5.8 tablespoons of dry food (Science Diet Indoor Kitten) and 1.4 ounces of wet food (brand and flavor varied) over the winter of 2016-17.
If you'd like to visualize the daily breakdown of cat food consumption with the help of two basic (interactive!) line charts, please click the link below. As a bonus, you will also get to visualize the cat himself!
I wanted to try dabbling in D3 and responsive web design, and I wanted some real, but not too complicated data to start me out. I also planned to put the results on this blog, but I'm ambivalent about putting anything too meaningful online. Cat food seemed like an innocuous topic aside from exposing us as arguable helicopter parents and definite nerds.
A few weeks after Pogo moved in, we began writing on the dry erase board on the fridge every time we fed him. Kibble was measured in tablespoon (T) scoops and wet food was estimated as a fraction of a 5.5 ounce (Oz) can. I copied the data over to a Google spreadsheet every time space ran out. After two months, we had a respectable-sized dataset detailing Pogo's food consumption as he grew from an 11 week old kitten who loved to attack rubber balls from the safety of an empty 12-pack into a 6 month old pre-teen who enjoyed batting at bouncy spheres from the shelter of slightly larger boxes.
Cat food consumption was tracked for 96 days, from Nov 24, 2016 through Feb 27, 2017. Over this observation period, Pogo ate an average of 5.8T dry and 1.4Oz wet food per day. Daily dry food consumption ranged from 2 to 8T, while wet food was between 0 and 1.83Oz. Wet food remained fairly consistent at either 1.38 or 1.83Oz daily (1/4 and 1/3 of a can, respectively), dipping below 1.38 for only 7 of the 96 days. Dry food followed an upward trend until around the new year, increasing a tablespoon every 11 days from 4 to 7T (R2=0.48). It then leveled off to just under 6T for the remainder of the observation period.
Nothing particularly surprising was identified by this study. Increasing dry food consumption in the first 5 weeks followed by a flattening off might have corresponded with fluctuations in Pogo's growth rate and subsequent hunger levels. Several days of decreased or missing wet food were explained by unusual circumstances. For instance, on Dec 16th and 17th we ran out of wet food, and on Jan 8th Pogo's food was restricted in preparation for neutering. Other variations in apparent appetite for wet food may have been attributable to flavor preferences, which we did not track. On a few ocassions when wet food consumption was down, more dry food was consumed, possibly to compensate, but there are not enough data to make a strong assertion.
Limitations and areas for further study
A limitation of this study is that the use of hundredths of an ounce in reporting wet food consumption is drastically misaligned with the actual precision level at which study was carried out. The real measurements, as fractions of a can, were lazily eye-balled and haphazardly dolloped. Their accuracy is more likely to within an ounce. Relatedly, the distinction between provision and consumption of food was not well defined. There may have been times when Pogo would have eaten more food if we had provided it, while at other times he did not eat all of the food that was available, and we did not always adjust the data accordingly. Pogo's tendency to "bury" food that he did not finish may have indicated satiation in several instances.
As mentioned above, this "study" is—by design—pretty boring. Any actual discoveries about cat food consumption were incidental to the main goal of producing a toy dataset. Future research could be made more interesting by tracking additional phenomena such as water intake, exercise, excretion, or weight gain, and exploring how these correlate with food consumption. For instance, does increased hydration correspond with less consumption of wet food? How much does water or food intake go up after exercise? To what extent does food consumption increase with weight gain and vice versa? Water was initially tracked but was dropped from the final report due to haphazard record-keeeping. Excretion didn't seem fun to track. Coming up with a metric for exercise was too complex for the scope of this study, and data collection would have involved monitoring Pogo's behavior more consistently than was feasible. Similarly, a few data for weight were obtained during vet visits, but later attempts to gather data were foiled by the impracticality of convincing Pogo to stand still on the scale we have at home, which is nominally for baking.