The results of my adventures with the all(ish) potato diet are in, and they are unequivocal. The reason for the ish caveat is that I actually ate more than just potatoes by including albacore tuna and egg whites for protein.

Basic Parameters

  1. Ensure a minimum intake of 1.5g of protein per kg of body weight
  2. Only low fat protein sources: potatoes, egg whites, albacore tuna
  3. Once protein requirements were met, consume only potatoes for remaining calories.
  4. Consume 1500 kcal per day, 500 below BMR.
  5. Evaluate progress after one week, continue for an additional week depending upon results.

I monitored my weight for about 10 days prior to engaging on dietary modifications to establish a baseline weight. Subsequently, I consumed variants of 1500 kcal isocaloric diets that provided the bulk of the calories from either potoato CHO or rice CHO. In all cases, the amount of consumed protein was constant and provided by egg whites and albacore tuna in order to minimize ingested fat while on the high CHO phases, resulting in single digit intake averaging about 8 grams per day.

Changes in body weight

After an initially promising couple of days, as you can see from the graph, we suffer a reversal of fortune and weight starts to climb back into pre-intervention levels. Switching from potatoes to rice seems to improve things initially, but weight starts to climb again after the initial switch. This is particularly interesting because calories ingested during the baseline were about 20 - 25% higher than with either rice or potatoes:

Caloric Breakdown

Were it not for the data of Nov. 1, where I ate somewhat less that my usual fill, the 500 – 600 calorie difference between the baseline diet and the intervention diet would be much more readily visible in the graph.

Epic Fail

What would be the definition of an epic fail in the body recomposition world? How about taking in a significantly reduced calorie diet and turn that into a weight gain?! Does that qualify? I believe it probably does. The trend lines in the graphs below tell the whole sordid story. From a slight downward trend during the baseline to a dramatic reversal while eating potatoes, and only a slight improvement, albeit still trending upward, while eating rice instead of potatoes:

In the trend graphs, rather than showing my actual weight, I wanted to have something that was comparable across each intervention, so I transformed the data by standardizing each observation. This entailed calculating the sample mean, subtracting that from the observation, and then dividing the result by the sample standard deviation. The net result of all of this is that the values are dimensionless, and in each of the graphs you will note that the y-axis scale does not change.