What is a calorie restricted diet?
A calorie restricted diet is an eating plan that limits the daily intake of calories. It is the same concept as a kilojoule restricted diet with the only difference being in the unit of energy measure – calories vs joules. Calories can be taken in through food (input) or expended during activity (output) and the purpose of a calorie restricted diet is to shift the balance between input and output to yield a desired body weight. Too many input calories (food) = weight gain. Too few input calories (food) = weight loss.
The terms calorie-restricted and calorie-controlled are often used interchangeably. Many prefer the latter term, calorie-controlled, as it indicates that the goal of the dietary change is to control rather than restrict calorie intake through food. Similarly it can be applied to other weight control measures like an exercise schedule.
Getting Started With A Calorie Restricted Diet
Ideally a person should first assess their eating habits by keeping a calorie counting diary for at least one to two weeks prior to starting a calorie restricted diet. Many who are overweight or obese are in denial about their eating habits. The reality is that an excess of calories causes weight gain, despite eating few meals in a day or attempting to eat small meals. The excess may occur in eating a single large meal or eating small portions of high calorie foods.
By keeping a calorie counting diary and analyzing the calorie intake at the end of the week, one can clearly identify where the excess of calories may lie. Use the weekly calorie count sheet and list of calories in common foods to first analyze dietary habits. This helps to create awareness about incorrect eating habits.
Defining a Calorie Goal for a Diet
In order to develop a calorie restricted eating plan, a person first needs to define a goal calorie input. This means the number of calories eaten per day.
The average 70kg (155 lb) man needs about 2,500 calories per day while a 70kg (155 lb) woman needs about 2,000 calories.
This is the calorie input through food and it is for a moderately active person.
If sleeping all day, the same 70kg (155 lb) man would only require about 1,650 calories per day, whereas the 70kg (155 lb) woman would need about 1,450 calories per day. This is known as the basal metabolic rate – the bare minimum calories to sustain life and maintain health in the human body.
Therefore a person aiming for this body weight (70 kg / 155 lbs) should be slowly reducing calorie intake to these levels. However, aiming for this goal at the outset can often lead to a significant loss of calories per day that may be difficult to adjust to. Therefore it is best to start with weight loss by reducing the daily calorie intake by 500 calories per day.
For example, a person eating 4,000 calories per day should first aim for a daily calorie intake of 3,500 calories per day and this can be further reduced by 500 calories per day every 2 to 3 weeks.
Never consume less than the basal metabolic rate. Calorie intake of less than 1,200 calories per day in an adult can cause fatigue and some nutrient deficiencies. A calorie intake of less than 1,000 calories per day will lead to severe fatigue and nutrient deficiencies and adversely affect a person’s health.
How to create a calorie restricted diet
- Identify your goal daily calorie intake. Be realistic about yours goal – weight loss does not occur overnight.
- Adopt an eating plan with foods that you enjoy rather than a generic diet. Use the list of calories in common foods to identify which foods you would prefer and within your calorie quota. Take not of the portion sizes.
- Monitor your body weight on a weekly basis. Focus more on the centimeters / inches in the first few weeks rather than just the kilograms / pounds.
- Start an exercise plan that will allow you to burn between 300 to 500 calories per day. This will help offset any extra calories that may not have been catered for in the eating plan.
- Focus on realistic body weight goals. Aim to lose about 1.5 to 2 kg (3.5 to 4.5 lbs) per week – it is a realistic goal and will not adversely affect your health with sudden weight loss. Also consider your waist size because you may not lose weight in some weeks but your inches may decrease.
- AVOID FAST FOODS. These convenience meals are packed with high calorie foods. Your favorite big burger meal from a well known burger franchise has 1,350 calories in a single meal – burger + fries + cola. That is over half your daily calorie intake in one meal.
- Always read the food packaging carefully. The portion size and calorie content is clearly marked but be aware of the number of calories in the portion size that you are eating.
- Eat more rather than fewer meals. A constant intake of a moderate quantity of calories will maintain a constant metabolic rate. Excess calories will be stored as fat. Insufficient calorie intake will lead to fatigue. If the daily calorie quota is 2,000 calories, it is best to eat 3 meals of 500 calories with 2 snacks of 250 calories in between.
How to modify a calorie restricted diet
Sometimes a generic diet for losing weight may not suit person’s personal or cultural tastes. If certain foods are to be removed from the diet, it should be replaced with calorie equivalents from the calorie list. Replacement foods should also belong to the same food group and have the equivalent in fat and protein content.
A calorie restricted diet may also need to be modified for changing calorie goals. If the target weight has been achieved for the specific diet, the daily quota may need to be reduced. Simply reducing the portion size by up to 30% may be sufficient but if monotony is setting in, then new foods with equivalent calories should be identified.