Fruit juice is made by extracting liquid from fruits and vegetables, removing the pulp that contains most of the fiber. This process results in a drink rich in vitamins, minerals, and antioxidants.
The key difference between whole produce and juice lies in what is removed: the skin, seeds, and pulp, which are the parts richest in fiber. Many people use juice for weight loss, ranging from incorporating it with meals or replacing one or two meals daily, to undertaking complete fasts where only juice is consumed for several days. The primary goal of this method is to reduce calorie intake for rapid, short-term weight loss. However, while fruit juice can lead to quick weight loss, it carries many risks and does not offer lasting results.
Juice leads to rapid but unsustainable weight loss
The fundamental principle of weight loss is achieving a calorie deficit. When meals rich in protein and fat are replaced with low-calorie vegetable and fruit juices, the total energy intake significantly decreases.
For many, substituting meals with fruit juice can result in losing a few kilograms in just one week. However, nutrition experts warn that most of this initial weight loss consists of water and glycogen stores, not sustainable body fat. When a normal diet resumes, the body tends to store weight again to compensate, leading to rebound weight gain.
Lack of satiety
Satiety is regulated by hormones in the stomach and brain, which respond strongly to fiber and protein. Fruit juice has almost all its fiber removed, which is crucial for slowing digestion and prolonging feelings of fullness. Additionally, liquid foods, especially those high in natural sugars, generally provide less satiety than solid foods. A person can quickly drink juice from three apples, but eating three whole apples takes more time and promotes longer-lasting fullness.
Negative impact on metabolism
Prolonged, excessive calorie restriction forces the body into an "energy-saving" state. Since juice provides almost no protein, the body must break down muscle for energy, reducing muscle mass. As muscle mass decreases, the metabolic rate also slows. Simultaneously, the body automatically reduces energy expenditure, making future fat loss more challenging.
Excessive juice consumption not only affects weight but also threatens overall health. Juices do not provide enough healthy fats (omega-3), fat-soluble vitamins, and many vital minerals. This can lead to anemia, osteoporosis, and negatively impact cardiovascular and brain health.
Consuming large amounts of dark leafy greens like kale and spinach can increase oxalate levels. Excessive accumulation of oxalate may cause kidney stones or impair kidney function. Individuals relying solely on juice also risk protein and essential micronutrient deficiencies, which are vital for immunity. Consequently, the body becomes more susceptible to illness and recovers slowly. The very low calorie intake from juice can easily cause hypoglycemia, leading to dizziness, poor concentration, and reduced energy, impacting daily activities.
If you enjoy juice, you can still consume it judiciously to support health. Prioritize greens, limit fruits to reduce sugar content, or choose smoothies to retain fiber. Additionally, combine juice with protein-rich meals like meat, fish, and eggs, and avoid relying solely on juice for extended periods.
Bao Bao (According to Healthline)
