The lemon cleanse diet is typical. For 10 days you have a lemonade drink, saltwater, and an herbal tea laxative. Participants do lose weight as they are taking in very few calories, but also lose muscle.
It is debatable if the lemon juice helps or the 10 day fast works just as well with other liquids.
The popularity of such diets is partly because people believe all fruit juices are healthy since they are “natural”, and full of vitamins, minerals, and antioxidants
However, many people do not recognize that fruit juice sometimes contains just as much, if not more, sugar and calories than sugar-filled soft drinks (1).
While fruit juices do have many nutrients, they are not magical, and for weight loss purposes they do not outweigh the negative effects of the sugar content.
Do NOT assume it that all fruit juices are healthy drink choices, especially for weight loss
Processed Fruit Juice Isn’t the Same as Fresh Squeezed
Even juices that are labelled “Not From Concentrate” or “100% Juice” have additional additives and flavor enhancers, and manufacturers often use deceptive labeling.
Fruit juice is not often packaged and sold immediately after being squeezed from the fruit. It may sit in an oxygen-depleted holding tank for up to a year before it is put in a package and ends up in stores (4).
Much of the flavor is lost during this storage period so manufacturers enhance their products with “flavor packs” which is not noted on the label (5).
Even high quality juices are a far cry from fresh squeezed.
Inexpensive juices are even worse, as many of those are just sugar-filled water with a little fruit flavoring.
Even the highest quality juice goes through a manufacturing process that causes it to lose flavor which requires producers to add “flavor packs” to restore its natural flavor.
More Sugar than Soda
The high sugar content of fruit juices is often overlooked, and people consider them to be a healthier choice than sodas, but this is not always true.
8 ounces of Coca Cola classic contains 97 calories and 27 grams, or 7 teaspoons, of sugar.
In comparison, an 8 ounce serving of grape juice contains 152 calories and 36 grams, or 9.8 teaspoons, of sugar!
From this chart, Pineapple, Cranberry, and Apple Juice all have higher calorie and sugar content than Coca Cola
Some Fruit juices contains just as much or more sugar and calories than soda.
Liquid Calories are Uniquely Fattening
While all foods contain calories, our bodies do not process them the same.
Our body has a naturally set weight point, and the brain adjusts feelings of hunger in relation to consumption of solid foods around this (8).
Liquids have a very different effect on our bodies response than solid foods. They do not promote feelings of fullness or satiety.
This is one of the reasons sugar-filled, high-calorie drinks are often to blame for obesity.
One study showed that a child’s risk of obesity increased by 60 percent for every serving of sugary drink they consumed (11).
Controlled studies proved that consuming sugar in liquid form can cause insulin resistance, raise triglyceride levels, negatively impact LDL cholesterol, and cause accumulation of belly fat in as little as ten weeks (15).
Fructose can be the worst form of sugar
Many people assume Fructose is better for you than the Sucrose in soda since it comes from fruit and is more “natural”
Actually, Fructose is worse if you consume more than your body needs
Your pancreas produces insulin in response to excessive blood glucose levels to signal transport of the glucose to muscles, glycogen storage in the liver, and lastly as storage in fat cells.
Insulin also regulates the production of the “hunger hormone” Leptin, which signals satiety, or fullness to the brain so you stop eating.
Sucrose is about 50% glucose and 50% sucrose (16).
When sucrose is consumed it is easily metabolized to fructose and glucose. The body uses the glucose for energy and the fructose is metabolized by the liver.
Your pancreas does not produce insulin in response to consumption of fructose (17).
Insulin regulates production of the “hunger hormone” Leptin. Lower levels of Leptin lead to overconsumption (18).
Fructose is only metabolized in the liver where it is converted into glucose, glycogen, lactate, and triglyceride (19).
In another study done with actual fruit juice, participants were asked to drink just 16 ounces of grape juice a day for three months.
In that short amount of time, researches noticed increased insulin resistance and waist circumference (27).
A third study showed that drinking 2 or more 8 ounce servings of fruit juice a day more than doubled the risk of gout in women (28).
Consuming too much fructose can be hard on the liver, and lead to insulin resistance, metabolic problems, and weight gain.
Whole fruit is much more filling
Drinking a glass of fruit juice prompts VERY different response in our bodies compared to eating a whole piece of fruit.
While fruit juice does contain vitamins, minerals, and antioxidants necessary for good health, it is not as nutrient-rich as whole fruits or vegetables.
However, it contains none of the fiber of an orange which makes it a poor choice compared to whole oranges or vegetables (32).
Fruit takes more effort to chew and swallow, and whole fruit is hard to overconsume since it is very filling (33).
The sugars in fruit also break down during digestion more slowly than those in fruit juices since the pulp contains a lot of fiber.
Because fruit juice has no fiber and is easy to consume in larger quantities than whole fruit, many people ingest too much sugar.
Whole Fruit Good – Fruit Juice, not so much
Despite the fact that nutrition guidelines state that a serving of fruit juice counts towards the daily recommended allowance of fruit, in many cases it is not a good choice.
While it may seem healthy because it contains fruit, fruit juices are actually more similar to sugary sodas and should be enjoyed only in very small quantities, if at all.
Whole fruit contains more fiber and nutrition, is more filling, and always a better choice than juice.
You might also want to read about Dried Fruit – is it good for weight loss.