Mainly for those worried adding fruit to Huel because of the bad reputation of sugar in fruit juices or smoothies.
The main problem with sugar in large doses is that it can overwhelms your liver. This in turn can lead to your liver forming insulin resistance, liver disease and you getting unwanted weight gain through the livers failure to metabolise the sugar and it being turned into fat.
Fortunately fiber could be a saviour here. See the main reason people claim fruit smoothies are bad is that the insoluble fiber that acts like a huge sponge and aids the bodies absorption of sugar is made smaller which basically renders it useless, your body is then being bombarded with sugar similar to the way drinks like cola do.
But luckily the main source of fiber in Huel is Oats which happens to be an even better sponge if you reduce particle size of the fiber. This probably why so many people experience discomfort moving to a Huel, feel very full and also lose weight. Food containing fiber takes up more space than food that doesn’t, Not only will you feel more satisfied after you eat, but that feeling of satisfaction will last longer because your food moves slower through your digestive system.
So I think consuming sugar with Huel is not only very safe but also potentially beneficial as it is a great source of sort term energy, so go for it! Unfortunately the idea that blending fruits increases nutrient value is most likely pseudoscience to increase the marketability of juices and smoothies.
This is not to say I advocate adding large amount of sugar to Huel. For example I personally suffer with Candida issues which feed off sugar and overwhelm the good bacteria in your gut, so I personally need to keep my sugar intake low.
Finally, on the subject of fiber, there is research suggesting that grinding up vegetable fiber into smaller pieces makes it more effective in reducing cholesterol.