How very random! Is that the values for a healthy diet or a weight loss diet though?
Umm, it depends. Obviously you can lose weight by just reducing calories, regardless of what the ratios are.
Some diets suggest that you keep roughly to those ratios and then increase the portion sizes to maintain.
In the UK, many of the diets go for much lower fat. That's still the trend here. I'm not sure what they suggest for maintenance, but I should imagine, to continue with a lower level of fat.
I would say, in an ideal world the people who make these ratios (which are similar in other parts of the world), are thinking for healthy eating and weightloss. Since most go for the eat healthily but less calories and move more stance.
We know that it isn't always as easy as that, so there's plans out there like SW who find way to reduce calories even if it means changing the ratios to make it feel easier and so more sustainable. Absolutely fine in the short term IMO, as long as the fats and protein don't go too low as both are essential for health (especially protein when you are dieting)
I should add that Cambridge also 'tweak' the ratios but again, it's just short term....to make the diet more sustainable.