As spring approaches, you may be considering dusting off your juicer or blender to start your pre-summer weight loss plan. Our Nutritional Solutions Registered Dietitians have reviewed juicing as a means of achieving this goal and here’s what we have to say.
What is it?
This diet goes by many names which range from juice fasting to juice detoxing and is a diet in which a person consumes only fruit and vegetable juices to obtain the nutrition they need while abstaining from consuming foods. These diets can last anywhere from a few days up to several weeks. The juices consumed are typically freshly made or squeezed rather than those that are commercially available.
Are there any advantages of this diet?
If you’re not into eating fruits and veggies, this diet or “detox” is one way to get them in. Selecting a variety of fruit and vegetable juices will help you to get a good mixture of vitamins, minerals and other phytonutrients into your diet. There is evidence to suggest that a diet rich in vegetables and fruits (more than 5 servings per day) is associated with a decreased risk of coronary heart disease and stroke.There is also evidence to suggest that eating a plant-based diet decreases your risk of cancer, although the cancer reducing benefits are achieved as a result of consuming vegetables, fruits, whole grains, legumes, seeds and nuts .
It goes without saying that you will be missing out on all of the other nutrients that are found in the rest of the foods you will be avoiding when you follow this diet. In addition, in order to get the maximum benefit from fruit and veggies, we recommend you enjoy them in their whole, most original form either raw or cooked using healthy methods. Fruits and vegetables can be eaten on their own or as part of balanced, mixed meals. Many juicing machines require that you remove the skin of the fruit and vegetables before you place them in the juicer and they also leave behind the pulp, which is where most of the fibre is found. You could add some of the pulp back into your juice but won’t get the full amount of fibre. Fibre, both soluble and insoluble, plays a key role in optimizing gut health which plays a role in healthy immune function and weight loss. You may also miss on some nutrients that are sensitive to heat or light if you don’t drink your freshly prepared juice soon after it has been made or within the same day.
Can this help me lose weight?
One of the key principles to losing weight is taking in the correct amount of energy you require to maintain your ideal weight, taking into account a number of personal factors such as, but not limited to, your height, sex, age, physical activity levels and health status. Many juice recipes require that you use a number of portions of fruit and vegetables. You could be taking in up to four fruits at one time, many more than you would manage to eat if they were whole. The kilojoules can start to add up if you drink large volumes, even though you are not taking in other foods. Juicing also results in the sugars in the fruits and veggies being freely available and are quickly absorbed into your bloodstream. Your body secretes insulin in response to this, as a means of allowing the sugars into your cells where it can be used for energy and bringing your blood sugar levels back to normal. By raising your insulin levels throughout the day, your body stores fat and prevents you from using fat as a source of energy. Both of which are not helpful when trying to lose weight. You may also feel like you don’t have the energy to do any exercise, an important aspect of wellbeing and healthy weight management. In cases where you severely restrict what you consume, rapid weight loss may occur but this is usually in the form of water and glycogen (the body’s carbohydrate stores), rather than fat. You may also feel tired and dizzy while you are following this kind of diet.
Another important factor in losing weight is the correct amount and quality of carbohydrate, protein and fat in your diet. Juices that are made solely of fruits and vegetables provide very little protein, fat and fibre, all of which have a role to play in helping you to stay fuller for longer. You may be tempted to opt for less healthy options when hungry, which can hamper your weight loss efforts. Not eating enough protein could also mean you lose muscle over the longer term, which can affect your metabolism and your weight.
Your body has a well-developed system to remove waste and toxins and is constantly filtering out, breaking down and excreting toxins and waste products. Your body uses various organs such as your skin, digestive system, liver and kidneys to do this work. The mechanisms that link the food and nutrients we eat to the processes of detoxification in our body are still being explored but it is suggested that phytonutrients (‘plant’ nutrients) and more traditional nutrients that build and support your enzyme systems have a role to play in these processes. Whilst you can get many of these nutrients by creating juices using a combination of fruits and vegetables, you will miss out on the protein required for some of the detoxification processes and the other benefits that their whole forms will provide you with.
Further to the above, we recommend that if you are taking prescription medication, that you consult with your medical doctor before starting this kind of diet. Certain fruit juices influence the absorption of some medications and can also result in the medications being less effective.
The juicing or detox diet may be a beneficial addition to the diet of those who find it difficult to reach their daily target of 1-3 fruit servings and 3-5 vegetable servings. For these individuals, juicing may be an excellent way to enjoy the benefits of the nutrients these foods contain. Care must be taken not to exceed the recommendations of 2 Fruit servings per juice and it is essential that fibre from whole grain sources be added to the diet to reach daily fibre targets. A juice fast is not necessary for detoxification as the body is constantly in a state of detox and a healthy, balanced diet which includes protein, quality carbohydrate and fat sources can provide all of the necessary phytonutrients and even more important organic substrates, to better optimize detoxification. Weight-loss is not necessarily guaranteed through a juice diet as some juices can contain large amounts of sugar and contribute excess kilojoules, above the daily energy requirements.