“Low-calorie diet”- this is something all of us have heard or followed at least once in our life in an attempt to lose weight. What is a low-calorie diet? Why do we need to consume less calories to lose weight?
A low-calorie diet is one in which the aim is to consume the minimum calories that is required by our body. The calories that are not used by the body are stored as fat hence the low-calorie diet to lose weight.
The macro nutrient that is the avoided the most in a low-calorie diet is fat. This is because fats contain the most amount of energy (Calories) i.e. 9Cal/g as opposed to proteins or carbs that contain 4Cal/g energy. However, not all kinds of fats cause weight gain. (Read Healthy Fats for Weight Loss, 10 Proven High Fat Foods That Aid In Weight Loss)
Another generalized misconception about Fat is that, it’s bad for health. Therefore, it is important to understand the kinds of fat that are present in the food. Fats present in natural foods are of two types- Saturated fatty acids and Unsaturated fatty acids.
Saturated fatty acids (SFA) are usually called as bad fats and unsaturated fatty acids as good fats.
The oil we use or most of the fat rich foods we consume on a daily basis contain mostly SFAs.
Therefore, we tend to consume much more than our requirements that causes adverse effects on health and leads to weight gain. Also, SFAs in general promote fat accumulation .
The consumption of Unsaturated fatty acids on the other hand present in foods like nuts (walnuts, almonds), fish, avocados etc. is less than that of SFAs.
These fats are extremely essential for brain health, they lower the level of bad cholesterol in our body (LDL), they are important for heart health etc. No association has been found between consumption of unsaturated fatty acids and weight gain.
It was for the above-mentioned misconceptions that avocados that are rich in fats were avoided in a weight loss diet. Let’s have a look at the nutritional profile of avocados and find out if they really cause weight gain.
Avocados – a nutrition profile
Avocados are different from other fruits. Other fruits are mainly rich in carbohydrates but avocados are rich in fats.
They have a rich and creamy texture which is attributed to the presence of Fats (Monounsaturated fatty acids- MUFA, Polyunsaturated fatty acids-PUFA and Saturated fatty acids-SFA) in them .
They are widely used in the preparation of the Mexican dish- Guacamole. They taste delicious and are easy to incorporate in dishes because of their texture. Apart from being delicious its nutritional profile is a complete winner.
Each 100g of avocado contains 1.96 g proteins, 15 g fat (MUFA, PUFA and SFA), 6.8 g dietary fibre, 8.6 g of carbohydrates and 72 g water .
These fats present in avocado are considered as good fats and have numerous health benefits such as promote a healthy lipid profile, increase the bio-availability of fat-soluble vitamins, and help maintain cardio vascular health among many others .
They are rich in vitamins A, B and C. They contain minerals such as potassium and sodium in abundance. They also have antioxidant properties2.
3 Benefits Of Avocados In Weight Loss
As mentioned earlier 70% of avocado is water the rest is dietary fibre and oil which play a pivotal role in causing satiety . The factors that are responsible for bringing about weight loss are discussed in detail below:
1.Avocados help control appetite
Each 100 g of avocados contain 6.8 g of dietary fibre that is almost 27% of our total fibre requirements for a day. Studies have suggested that dietary fibre causes post meal satiety and reduces hunger. This reduction in hunger may cause weight loss .
The reduction in appetite is due to the soluble fibres. Soluble fibres become viscous in the stomach and slow the gastric emptying time making a person feel satiated and curbing appetite .
Consumption of avocado has been related to a better-quality diet and lower BMI and waist circumference .
Avocado related weight loss is mainly attributed to satiety. A human based clinical study was conducted to determine whether avocado leads to satiety and reduction in energy intake.
This study concluded that consumption of half an avocado along with a meal increased satiety, reduced hunger resulting in reduction in subsequent food intake as compared to the subjects who did not consume avocado with the meal.
The subjects who consumed avocado along with their lunch showed around 23% more reduction in hunger and 28% more satiated than the controls .
Increase in water intake has often been related to satiety. A human based clinical study suggested that the increase in the incorporation of water into the food increased the post meal satiety .
Since avocado contains 70% water, this property can be associated with enhanced satiety and reduction of hunger that in turn leads to weight loss.
What does this mean?
Studies have suggested the association of high water content in food and satiety. Therefore, avocado containing 70% water may cause the feeling of fullness and curb the appetite that results in loss of weight.
The high fibre content in them causes satiety thereby reducing the food intake and causing weight loss.
2.Avocados are a rich source of healthy fats
Each 100 g of avocado contains around 10g of MUFA, 2 g of PUFA and 2 g of SFA2.
Unsaturated fatty acids (PUFA and MUFA) are known to cause satiety1. Ingestion of fat reduces the gastric emptying time thereby causing the feeling of fullness and subsequently causing weight loss .
Several exploratory trials have also suggested the role of MUFA rich diet against abdominal fat accumulation and diabetic complications .
A study found that unsaturated fatty acids caused the elevation in the secretion of satiety hormones pro-opiomelanocortin (POMC) and a decrease in the expression of a hormone that causes hunger i.e. Melanin concentrating hormone (MCH) .
Another study conducted on obese women suggested that a high PUFA diet causes a decrease in hunger hormone Ghrelin and increase in satiety hormone Peptide YY (PYY) as opposed to a high SFA diet.
A human-based experimental study suggested that addition of 200g of avocado to a low-calorie diet did not compromise weight loss as compared to the control who were fed equal amounts of a mixture of dietary fats such as margarine or oil . This clears the misconception that avocados cannot be consumed in a low- calorie diet as they may cause weight gain.
What does this mean?
MUFAs and PUFAs present in avocado regulate the satiety and hunger hormones that cause weight loss. Several studies have suggested that a high MUFA rich diet prevents fat accumulation.
3.Avocado extract influence genes affecting fat metabolism
In one study, it was found that avocado extract (without fat) causes a reduction in BMI, fat mass and plasma cholesterol (LDL) levels. ‘
This was due to an increase in the expression of adiponectin and the PPAR-gamma genes. These proteins are responsible for the breakdown of fats .
What does this mean?
The other non-fat components present in avocado bring about a reduction in BMI, Fat mass and plasma cholesterol. However, the mechanism of which is not completely clear.
How much avocado to consume for weight loss?
Avocados are high in calories. More than 1 fruit a day would contribute to excess calorie intake. Half an avocado prior to a low calorie meal can help control appetite and assist in weight loss.
Avocados are perfectly fit to be included in a low-calorie diet and do not cause any weight gain. But, the fact that they are high in calories cannot be completely ignored.
Therefore, if you are on a low-calorie diet consumption of not more than one avocado a day (around 100g) will not cause any weight gain.
They have been associated with weight loss in terms of satiety. More evidence is available explaining the role of “good fats” present in them and their role in satiety and weight loss. But, recent studies have shown that defatted avocado extract also brought about a reduction in BMI and fat mass.
Therefore, we can say that it’s not mainly the MUFAs and PUFAs that play a pivotal role in weight loss but also all the other nutritional components (fibre, water, etc.) that contribute equally to weight loss. However, more concrete evidence is required to understand the mechanism behind these nutritional components and their role in weight loss.
Till date no toxicity has been observed in any of the human based clinical trials by the consumption of avocado, suggesting its safety and efficacy in losing weight.