I have read the study and some of the facts hidden from the media articles are:
1) The study believes incorrectly that the Paleo diet is Low Carbohydrate and High Fat (LCHF) and was configured as such.
2) The study was done on just 9 mice, over an 8-week period. Mice don't have the same metabolism or biochemistry, the number of them isn't anywhere near enough for scientific relevance, and an 8-week period is not really long enough.
3) The mice used were a genetically modified (GM) breed, which have altered metabolism so they develop severe obesity, type 2 diabetes and autoimmune conditions - hence they are already diseased, and aren't suitable test subjects or likely to produce any valid conclusions relevant to humans.
4) The Paleo diet is NOT low carb! It is high in vegetables and fruits, which contain mostly carbs! However the Paleo diet is very low in processed carbs, meaning no sugar, milk, breads, or any other grain products. This is a lot different to the study where the only carbs (6% of their diet) came from simple sugar, which is NOT a healthy carbohydrate!
5) The Paleo diet is NOT high fat! It has a higher fat content, but healthy fats found in eggs, avocadoes, fish, grass-fed meats, nuts and seeds. These healthy fats do not contribute to weight gain in body fat! In the study, a whopping 81% of the diets for the GM mice was fat! This isn't a valid representation of the Paleo diet either.
And I could go on... with such a biased study design, the conclusions just defy logic and contradict all independent research studies on nutrition and the causes of diabetes.
This is the problem with modern science that is dominated by limited research funding being provided by corporates wanting a positive spin in research studies so they can maintain their profits. As a result, studies like this one can be biased from the beginning and deliberately setup to get the results they want. Only by looking into the real facts of such studies with a critical eye can issues like this be found. Unfortunately the media don't check this and they just feed you what the biased press release tells them! It's corporate profits trumping over your health, sadly.
So what does cause weight gain and diabetes? Your diet certainly plays a part, with excessive sugar and processed carbohydrates causing high blood sugar levels and high insulin levels, with insulin converting the excess blood sugar into body fat. A diet higher in healthy fats does not raise blood sugar or insulin levels, and does not contribute to body fat!
There are many other factors that lead to weight gain and diabetes too - stress, lifestyle factors, environmental factors, poor sleep quality/quantity, and various nutritional deficiencies, and more. This is what I can help you with - finding the causes and resolving them, to bring you back to health!