Weight-loss diets: what should they consist of?

Weight loss,when necessary,can be tackled through diets,among other methods.There are a great many diets whose objective is weight loss,usually as quickly as possible.However,not all diets are suitable for achieving this,nor are they all based on scientific research.In order for a diet to be effective while not placing a dieter’s health at risk,it needs to meet certain requirements.

• Firstly,it should aim for steady,gradual,moderate weight loss.To achieve this without causing nutritional deficiencies it is normally necessary to consume between 20 and 25 calories per kg of bodyweight.
  For example,a woman who weighs 80 kg would require between 1,600 and 1,800 calories approximately,depending on the amount of exercise she takes.If we eat less than this we are at risk of protein,vitamin or mineral deficiencies that can cause medical problems in the long term and can speed up the rate at which weight is regained.The latter is an extremely frequent occurrence,as diets that are overly low in calories cause muscle protein to be lost and reduce the metabolic rate to such an extent that it causes the “rebound effect”.
• A balanced supply of nutrients is very important for healthy weight loss,therefore the different food groups should provide the various different nutrients.
  • A minimum amount of carbohydrates per day is necessary for the correct functioning of the nervous system (brain,nerves),heart and blood cells (red corpuscles,white corpuscles and platelets).Between approximately 40% and 50% of a diet’s calories should be provided by carbohydrates.Food groups that contain carbohydrates (such as those listed below) should not be excluded from one’s diet:
    • Cereals (wheat,oats,rye,barley,etc.)and their derivatives (pasta,bread,breakfast cereals,etc.).
    • Rice.
    • Tubers (potatoes).
    • Pulses.
    • Fruit and vegetables also contain small quantities of carbohydrates.

               Sugary drinks and other sweet foods also contain carbohydrates (sugar),however they are not recommended in weight-loss diets.

• • Between 10% and 20% of the calories in the diet should be provided by proteins.The foods that are richest in proteins are meat,fish,eggs,mature cheese and nuts.
  • Between 30% and 35% should be provided by fat.Fat is the nutrient that should be reduced the most,in spite of the fact that many diets with little scientific basis or proof may claim otherwise.

            It is vital to maintain this balance between the amount of nutrients provided by the different food groups,therefore weight-loss diets should include a wide variety of foods.-

 

In spite of this,many of the supposedly “miracle” diets are based around the consumption of just one type of food for a week (the grapefruit diet,the apricot diet,etc.)or a specific period of time,or around the exclusion of entire food groups,like diets excluding carbohydrates,protein-only diets or diets that are high in fat.In these latter diets,dieters are often allowed unlimited quantities of pork fat,bacon and foods that are very high in proteins and fats,like mature cheese,meat,oily fish,etc.

 

The downside of these diets is,as mentioned previously,the unbalanced and insufficient supply of nutrients,the consequences of which are very similar to those caused by overly restrictive diets.We require a minimum amount of carbohydrates per day,and if they are not supplied in the diet our body breaks down its muscle mass to form glucose in order to supply the cells in our central nervous system,red corpuscles,etc.

 

In addition,a diet that is overly rich in fat can lead to an increase in ketone bodies in the blood (acetone),which causes dehydration and other metabolic disorders,and,in some extreme cases,has lead to sudden death caused by arrhythmia.This is much more likely if a dieter has an existing cardiovascular risk factor,which is often the case in individuals suffering from obesity.

 

In other cases,diets that are overly fat-rich,that cut out foods containing carbohydrates and that are low in fruit and vegetables can lead to increased levels of cholesterol and triglycerides in the blood.