hey @Samantha Ribeiro
I agree with what sugarcubeOD shared. While smoothies and protein powders are not recommended on Whole30 and strongly discouraged, it is not a hard fast rule. The biggest reason Whole30 encourages real food over drinking our food is that the process of chewing food instead of drinking it helps accomplish a greater level of satiation and keeps us connected to the concept of choosing to consume real whole foods as opposed to quick drinks, fast foods, and not nutrient dense options.
The other issue with protein powders is the number of ingredients that are typically found in the ingredient list. After looking into the Sunflower protein powder options, I only found a couple that were pure sunflower seed protein. All the others had quinoa, pea protein, coconut sugars, and monk fruit extract among other things which are all off limits while on a Whole30. It is simply better to rely on whole sources of protein over powders.
I think the main thing with the fat is the possible toxins that could be in it. But that will also depend on how the meat was sourced. The better the source (grass fed and grass finished) the better the fat will be.
I'm not sure specifically why this happens but my guess is that because your body isn't used to processing that amount of added sugars anymore, it has to ramp up the systems to do so. Or maybe that happens to everyone but after Whole30 we realize how much energy we have and the people that are using sugar for energy are using it over and over for short term spikes which create deep drops afterwards.