Do diet teas and meal-substitute shakes work to lose weight?

Dear Trying to Diet,

When it comes to diet products, if it seems too good to be true, it probably is, as weight loss through dieting is often times short-lived and not sustainable. The cycle of losing and gaining weight that goes hand-in-hand with dieting, and the products that come along with it, can be quite harmful for many, both physically and mentally. When it comes to diet teas, herbs, meal substitution shakes, and other medical products, they all have a variety of effects on the body, Some act as laxatives, while others are simply low-calorie drinks. However, none of them are nutritionally or calorically dense enough to provide the nutrients your body needs. As for aspartame, research indicates that it's safe to consume for most groups (more on this in a bit). Digging into the "why" behind your desire to lose weight can be a great place to start, and then considering the variety of paths available to you from there can help you make decisions that are most right for you. With this in mind, whether you choose to diet or not, everyone can benefit from investing in and cultivating a healthy relationship with their body. 

First, while many of these products are advertised as weight loss aids, there's a slightly less appealing reality beneath this claim. Instead of aiding in weight loss, many diet teas and shakes are actually just diuretics or laxatives. Diuretics flush water from the body, while laxatives are intended to help clear the digestive system, and may be prescribed by a doctor, or found over the counter, to relieve constipation. Many diet products have natural ingredients like senna, aloe, dandelion lead, buckthorn, prunella, burdock, cascara or rhubarb root within them, all of which have a laxative effect. 

Weight loss products containing senna or other laxatives often promise to help "detox" the body, clearing waste that would otherwise be stored as fat. This claim isn't true, as the body naturally detoxes daily by processing food, storing nutrients, and removing waste, without the need for any extra intervention. By overusing laxative products and clearing nutrients from the body, you might actually slow your metabolism, which can cause weight gain. Weight loss products also may promise drastic weight loss, with some, like you mentioned, claiming results in just a few days or weeks. This type of weight loss is not only unrealistic, but also unhealthy, and even dangerous. Typically, physicians and registered dietitians maintain that a reasonable rate of weight loss is about one pound per week. Losing, or attempting to lose, more than that can result in caloric and nutritional deficiencies. 

Other diet products may also be marketed as "meal replacements". These drinks are often low in calories and intended to be consumed instead of a meal. These shakes can be filling, and often have some healthful ingredients such as fruits, vegetables, or protein, but aren't recommended to replace all meals. Many nutrients, such as fiber, are absorbed most effectively by the body through the consumption of whole foods, so a liquid diet, even with enough calories, might cause nutrient deficiency. 

You also mentioned aspartame briefly, which is a low-calorie sweetener that's used to lower daily sugar intake. Aspartame is made up of two amino acids, which break down in the body and are used to build proteins and maintain metabolism. Despite controversy over its potential health risks, the U.S. Food and Drug Administration (FDA), along with health regulators around the world, maintain that aspartame is a safe sugar substitute based on scientific studies. However, there's one exception. It's advised for people with phenylketonuria (PKU) to avoid aspartame because of their body's inability to properly metabolize phenylalanine, an amino acid found in dairy products and nuts. Additionally, a large body of research has indicated that it doesn't increase cancer risk. Generally, the recommended daily amount of aspartame consumed is no more than 50 milligrams per kilogram of body weight.

Given the popularity of these products, you're certainly not alone in considering whether or not they work of if they'll help you achieve your goals. That being said, there's not much empirical support for the effectiveness of dieting for sustained weight loss in research. However, people who are well-educated about dieting still do choose to do it in some form or fashion sometimes. Focusing on fostering healthy and consistent eating habits with lots of food choice, while also staying physically active, has proven to be the most successful way of losing weight and maintaining it. Restricting the amount and type of food eaten can also create an unhealthy relationship with food, which may develop into disordered eating, with potentially dangerous health impacts. Avoiding these negative impacts of dieting can be quite difficult, especially considering the immense pressure that many people face from family, friends and the media to ascribe to certain beauty standards. 

Ultimately, deciding to diet is a personal choice, but it might also be helpful to consider your reason for doing so. You mentioned the efforts you've gone through to lose 15 pounds and that your weight loss has plateaued. You may consider what weight meets your body's needs and if losing more weight or the efforts to maintain your current weight are supportive of your needs, both physically and mentally. Do you feel that you will be happier, or more loved if you lose 25 pounds? Do you think you will be more successful, or more appreciated, if you looked a certain way? If these are your reasons for losing weight, know that you're not alone. Many feel pressured to alter their bodies to better fit pervasive western beauty standards. Sometimes the cure for those negative or insecure feelings about body shape or size might not lie in the diet pills or weight-loss shakes, but in some good old-fashioned self-love and appreciation. If you feel that your thoughts about weight loss are pervasive or impacting your relationships, hobbies, or mood, it also may help to talk to a trusted friend, family member, or mental health professional. Finally, before making any changes in your diet or physical activity routine, it may be beneficial to talk with a health care provider or a registered dietitian. They can help answer any questions you have before making any changes that could affect your health.