This smoothie has a bit of everything for a wintery start to the day; a slow release of energy from the oats, the carbohydrates in the berries are released and digested slowly also. Both the raspberries and blueberries are of course jam packed with anti oxidants but there is also research in rheosmin present in raspberries which may increase enzyme activity and decrease a fat digesting enzyme, all in all ,maintaining a healthy weight.
Berries from the summer and autumn frozen straight after they are picked is the best way to eat berries through the bleaker months. The varieties that you get in the supermarkets this time of year have either been transported over great distances or have been grown in forced conditions, either way resulting in a substandard produce. Frozen berries may not hold their structure so well from the freezer but when a smoothie is in mind this is not an issue.