In some ways, it was good, in using identical twins, who are both doctors. And they were fairly scientific in their approach. However, they skimmed through a lot, and didn't say if they were doing regular exercise for example. Also, 1 month isn't a very long time to actually build up a body of evidence of differing results. For example, on a fat based diet, it takes at least 3-6 weeks for the body to fully adapt to running on ketones from fat rather than glycogen (sugar) from carbs. And that would explain why Xand struggled up cycling up Box Hill compared with his brother.
I switched to a fat based diet nearly a year ago, and lost 8 kg in 8 weeks, getting rid of my beer gut mainly. It was at least a month before I got back my full strength cycling, as initially it felt like I'd lost about the top 25%, and I felt rather sluggish.
Bearing in mind the mixed message from the program, I'm not sure many people will take much notice about stopping eating cheescake.