If you drink blended fruits and vegetables in the morning, you should first check your sugar intake.
Woo Chang-yoon, an endocrinology specialist, recently emphasized in a social media video to "be careful of 'this' when drinking vegetable and fruit juice, also known as detox juice." He said, "There's no problem with blending just kale, but when you start adding carrots and apples, the sugar content can spike rapidly. Consuming it in liquid form also speeds up blood sugar rise. If you're not confident you can move enough to burn it off, you need to control the amount."
Excessive sugar converts surplus calories into fat, increasing the risk of obesity and hyperlipidemia.
The destruction of dietary fiber is also difficult to overlook. When blended in a mixer, the fiber structure breaks down and cell wall damage accelerates nutrient oxidation. Satiety decreases, requiring larger quantities to feel full compared to eating raw produce. When consumed as a meal replacement, hunger returns quickly, increasing the risk of overeating at the next meal.
The alternative is to focus on low-sugar vegetables. Dr. Woo recommended, "Build your drink around vegetables with almost no sugar, like kale and broccoli."
Similar warnings have been confirmed in overseas research. Dr. David Cavan, an endocrinologist at Dorset County Hospital in the UK, pointed out that the sugar content in fruit smoothies can rival that of cola and may negatively impact health. He said, "When you turn fruit into a smoothie, you get a very sweet drink with a bit of fiber. In terms of sugar content alone, there's not much difference from cola." He added, "Whether it's natural fructose or not, sugar is still sugar, and it significantly affects blood glucose levels."
A diet high in sugar causes frequent hunger and excessive calorie intake, increasing the risk of obesity and related diseases. According to a 2013 study, people who ate whole fruits had a lower risk of developing obesity-related Type 2 diabetes, while those who drank fruit juice showed higher risk.
Dr. Cavan also warned that even diabetes patients in remission could see their health decline if they regularly consume fruit smoothies or cola. He cautioned, "If you continue to consume sugar this way, managing Type 2 diabetes is virtually impossible."