Written By Emily White

Flexible dieting is a weight loss program that has gained popularity because it allows a person to choose any food they want as long as it is within the macronutrient needs. It is for this reason that it also commonly referred to as If It Fits Your Macros (IIFYM). IIFYM purports that there are no ‘bad foods’.

Flexible dieting has become popular for its adaptable nature. This nature allows people to indulge in their favorite foods as part of their eating plan. There many approaches to flexible dieting e.g. calculating your needs and planning meals on your own.

How flexible dieting works

Flexible dieting is mostly viewed as a lifestyle rather than a dieting program. The control is in the hands of the dieter. There are no meal plans or food restrictions to be followed. Then is this is the case, how do people lose weight? A flexible diet means calculating calorie and macronutrient needs according to how much weight you intend to lose.

Before beginning a flexible diet, you should determine your total daily energy expenditure and macronutrient needs. Today, you can do this by using ‘macro’ calculators available on many websites that promote flexible dieting.

Calculating your energy needs

The total daily energy expenditure (TDEE) consists of the following:

  • Resting energy expenditure (REE). This includes the number of calories you burn while resting.
  • Non-resting energy expenditure (NREE). This consists of energy expended while exercising, in daily activities and in food digestion. It also includes calories used up in simple activities like fidgeting, shivering or standing.

About 60-70% of your total daily calories is used up be REE.

Calculate your total daily energy expenditure gives you an idea of how many calories you burn in a given day. The Mifflin-St Jeor Equation is the most preferred method of calculating your TDEE with many flexible diets advocating for its usage. It has been shown to be more accurate and effective in predicting calorie needs unlike other equations.

The equation outlines the calculation of total daily energy expenditure calculation as follows:

  • Men: (10× weight in kg) + (6.25 × height in cm) – (5×age) +5
  • Women: (10× weight in kg) + (6.25× height in cm) –(5×age) -161

The resulting figure is then multiplied by an activity factor. The final result gives the estimate for your total calorie needs. These activity factors include:

  • Sedentary with little to no exercise, × 1.2
  • Lightly active from 1 to 3 days a week, ×1.375
  • Moderately active from 6 to 7 days a week, × 1.55
  • Very active, every day, × 1.725
  • Extra active around twice or more in day especially for elite athletes, × 1.9

If the plan is weight loss, you will then subtract a percentage of calories from your TDEE to create a calorie deficit. According to many flexible dieting websites, a subtraction of 20% is best. E.g. a dieter with a 2000 calorie calculation would subtract 400 calories in order to lose weight.

The percentage is not restricted to 20%. You can decide what your calorie deficit is based on your weight goals and activity levels.

Calculating your macronutrient needs

After getting your calorie goal, it is time to calculate your macronutrient or macro needs. Macronutrients refer to the types of food your body needs most which include carbohydrates, proteins and fats. Macronutrients provide the body with calories and perform important functions in the body. The composition of the macros in daily calories is given as:

  • Carbohydrates account for 45-65% of daily calories
  • Proteins account for 10-35%
  • Fats account for 20-35% of total daily calories

There are macro calculators on various flexible dieting websites. The calculator gives you a result after you plug in your height, weight, age and activity levels and determining your custom macronutrient distribution. You can also calculate your macros by dividing your total calorie needs into specific carbohydrates, protein and fats percentages that meet your weight goals.

Flexible dieting allows you to adjust your macronutrient range to suit your lifestyle and weight loss needs. For significant weight loss, go with a lower carbohydrate range. If you’re an athlete then go for higher carbohydrate range.

It is also important to track your fiber intake during flexible dieting because fiber is a type of carbohydrate that the body cannot digest. The recommended intake of fiber is 38 grams for men and 25 grams for women.

Tracking your macronutrient intake

As a follower of flexible dieting, you must track your calorie and macronutrient intake to make sure that you stay within your goals. One of the easiest ways to do this is through mobile applications or using a flexible dieting website. Food tracking apps have databases that can allow you to look up any food and portion size and determine the calories within seconds. Apps help you keep track of your meals and snacks on the go without having to write everything down. The popular food tracking apps are MyFitnessPal and My Macros.

The benefits of flexible dieting

  • It is easy to follow. Despite people finding the calculation of calorie and macronutrient needs difficult, the diet itself is easy to follow. Flexible dieting does not require complicated recipes or food plans.
  • It can help you keep weight off long term. You are more likely to keep weight off long term with a flexible diet rather than a strict diet.
  • No foods are ‘off-limits’ which keeps you away from frequent cravings and binges
  • Gives you freedom of food choices at parties, restaurants or when limited food options are available.
  • Beneficial if you have specific nutrient needs such as athletes

Downsides to flexible dieting

  • Structure may be too loose for you if you lack strong self-control
  • No emphasis on micronutrients such as vitamins and minerals which are essential as well
  • You will need an understanding of nutrition and weight loss
  • You need to track every meal and snack

Flexible dieting is a simple program for weight loss. Popular and flexible. It gives you freedom of food choices. However, you will need self-discipline to hold yourself accountable for you food choices.