The notion that fruit should only be consumed alone or not within an hour of eating protein, to avoid digestive issues like gas, isn't supported by scientific evidence. The digestive process is complex, and while different foods might have various digestion times, the body is equipped to handle multiple types of nutrients simultaneously.
The idea that fruit digests much quicker than protein is overly simplistic. Fruits generally have a high water content and can digest relatively quickly, but they also contain fiber, which slows digestion somewhat. Proteins do take longer to break down, but this does not typically interfere with the digestion of fruits.
There is little credible evidence to suggest that eating fruit alongside protein causes digestive upset or gas. The body effectively uses digestive enzymes to break down food in a manner that can accommodate a mix of macronutrients. If there are specific digestive issues, it might be more relevant to focus on individual sensitivities rather than blanket rules about food combining.
For personal dietary concerns or persistent digestive issues, consulting with a healthcare professional or registered dietitian is advisable.