A close family member was recently diagnosed with type II diabetes, so I thought it would be appropriate to watch the Horizon episode ["Sugar v Fat"](https://www.imdb.com/title/tt3564506/) last night.

I was surprised at the results of their experiment. I expected the twin on the high-sugar diet to have gained weight. Both twins actually lost weight. Although the twin on the high fat diet lost more. They were apparently too low in their calculation of daily caloric needs.

It's one thing to see these results in a one month-long experiment, but in a real-life diet the effect of ghrelin (hormone that controls hunger) would be a huge factor. The twin on the high-sugar diet ate less protein and would be perpetually hungry. It wasn't clear how much willpower it took for the twin on the high sugar diet to eat within to the experimental parameters.

Did the twin on the high sugar diet really go a month with virtually no protein? That doesn't seem safe.

It wasn't clear if the twins were actually eating the same amount of calories. The twin on the high fat diet lost more, so I assume he ate fewer calories.

No mention of individual differences in the larger study results that they cited, only averages. I suspect there were individual differences, due to genetic differences. For example, the [CLTCL1 gene](https://www.theguardian.com/science/2019/jun/04/ancient-gene-mutation-could-protect-against-diabetes-study-finds).

The twin on the high-fat diet lost more muscle because he lost more weight. Training with weights would have reduced muscle loss.

This aired in early 2014. We've come a long way since then.

@barefootstache You might want to check this out.