Slimming smoothies: are they really that healthy?

The search for quick, innovative methods with long-lasting results to help with Slimming smoothies is a constant and, in this sense, the topic of  weight loss shakes  will never go out of style.

In the end, they are presented as products rich in vitamins and minerals essential to biological processes and, in theory, have fewer calories than a so-called conventional meal.

Regardless of the evolution of knowledge in the field of nutrition sciences, the premise for Slimming smoothies is quite simple: consume fewer calories and promote energy expenditure.

It is not surprising that the keys to the success of any intervention are the same year after year: prescription of a moderate energy reduction along with a program of physical activity practice and, not least, working strategies to fulfill the previous premises in order to maintain the results of the intervention over time.

In this sense, the consumption of shakes with the aim of losing weight may seem like an interesting idea since, in principle, it makes it easier to respect the premise of moderate energy restriction. But is it really that linear?

Slimming smoothies And Satiety

It has been shown that energy decompensation before a meal, drink or  snack  – that is, eating little and/or not eating for a long time – is associated with subsequent energy overcompensation.

This compensation is related to several factors, including age,  body mass index (BMI) , sex, time since the last meal and physical state of the same.

Several studies indicate that compensatory behaviors tend to be lower after ingestion of solid or semi-solid foods, compared to liquids.

This phenomenon may be associated with an incomplete energy compensation in the case of liquid meals, that is, in general, liquids are less satiating foods. The act of chewing, by itself, has a positive effect on the satiety index of food.

In contrast, and as in the case of weight loss shakes, the higher water content and speed of consumption of liquid foods – and therefore the time of oral exposure – have the opposite effect on this same index.

On the other hand, diets with extremely low energy values ​​can have a negative impact on the hormones that regulate stress mechanisms – including cortisol – whose possible appetite stimulation and relationship with compulsive eating behaviors can compromise the expected results.

Approaching the famous liquid diets – basically commercial weight loss shakes – they are characterized by having very low energy values ​​(less than 800 kcal/day) and are designed to provide very fast weight loss.

However, since 1998, it has been reported that these diets do not offer advantages in long-term weight loss when compared to other approaches, apart from the fact that they promote much greater initial weight loss.

It is even described that, after leaving these shakes to lose weight, the result is a weight gain of between 3.1 and 3.7 kg in the following 21 to 38 weeks.

On the other hand, prescribing physical exercise in conjunction with weight loss maintenance strategies after this type of diet does not reduce the amount of weight regained.

How to resolve the issue?

The key is portion control as prescribed by your nutritionist. The inclusion of two or three pieces of fruit will give the equivalent energy value, most of the time much higher than expected for the meal in question.

The fact that other foods such as seeds  or  dried fruit are often included   – whose cardiovascular benefits are undeniable – contribute to this exacerbated intake and you can easily obtain a shake with more calories than the traditional half-milk breakfast. and bread with butter.

Another issue has to do with consistency: choose to make your shakes with low-fat yogurt without added sugar or  kefir , in the quantities planned by your nutritionist, in order to make them more satisfying.

SLIMMING SMOOTHIES AND CALORIC INTAKE

Energy density is an extremely important variable for satiety mechanisms. Foods with lower energy densities (fruits, vegetables, etc.) tend to be consumed in larger portions than those with more calories (chocolates, cheeses, etc.).

Although the nutritional value is indisputable, even in quantities above necessary – as is often the case with weight loss shakes – foods considered “healthy” also lead to weight gain. The key, again, is proper portion control.

As previously mentioned, the secret to losing and maintaining weight is the correct balance between intake and expenditure and, therefore, even healthier foods, when ingested indiscriminately, can have a negative effect on this balance.

On the other hand, dietary protein has been associated not only with increased satiety but also with greater energy expenditure at rest, and therefore an increase in its intake is recommended, in association with a decrease in energy intake, in order to promote of weight loss.

In the case of weight loss shakes made exclusively with fruits and vegetables, the protein content of interest for maintaining lean body mass is basically non-existent.

How to resolve the issue?

According to the prescription, always include a source of protein with a high biological value ( whey protein ,  low-fat milk ,  low-fat yogurt ) in order to, once again, increase satiety in your slimming shake and guarantee a positive protein balance at the end of the day, sparing lean mass losses and the impact this can have on resting metabolism.

SLIMMING SMOOTHIES AND GLYCEMIC LOAD

In addition to what has been discussed above, the processing  of fruits and vegetables in weight loss shakes reduces their original fiber content, which has been shown to play a beneficial role in the risk of developing  obesity  and  diabetes ,  cardiovascular disease  (CVD) and some types of cancer ( oral, esophageal, gastric and colorectal cavities).

If, on the one hand, the viscosity of the fibers can delay gastric emptying, promoting better digestion and increasing satiety, on the other hand, it also affects the glycemic response after meals, “difficulting” the absorption of glucose and fatty acids.

Another issue that arises is the glycemic load (GL) of this type of meal. The glycemic load is defined as the increase in the concentration of sugar in the blood after ingestion of food, expressed as an increase in the area under the glycemic curve 2 hours after that act.

The GL of a food or meal is determined by the concentration of carbohydrates, the presence of fibers or other compounds that delay the absorption of sugars (such as resistant starch, for example) and its composition in water.

The presence of other nutrients such as proteins and fats contribute to variations in the glycemic load, modulating the time that food “stays” in the stomach – gastric emptying – and delaying its arrival in the duodenum, where most of it is absorbed.

It is not surprising that the physical processing of food products that are already poor in proteins and fats results in an increase in this parameter, contributing to a rapid absorption of simple carbohydrates and consequent exacerbated insulin response, leading to greater production of acids fat through carbohydrates.

The result, in the end, is greater accumulation of fat in reserves.

How to resolve the issue?

You can include seeds, nuts and even  peanut butter  – rich in fiber and monounsaturated fatty acids – in addition to high biological value protein sources in order to increase gastric emptying time, always in the amounts proposed by your nutritionist for your needs. calculated energies.