As you can see from this table. Calculated energy requirements for Anne to lose weight vary widely from 1200kcals to 1750 kcals per 24 hours. Is a 45% variation!

So the lesson here is not to take as gospel anyone prescribing a diet for weight loss based on a specific calorie deficit and value. To get an accurate calorie prescription you would need to take into account a lot more factors that influence our daily energy requirements. Factors such as muscle mass, medications, gut microbiome and other physiological states including pregnancy, lactation, illness etc.

Indirect calorimetry is the gold standard for measuring energy expenditure. Many indirect calorimeters are commercially available, but most of them are bulky, expensive and not 100% accurate.

So how then does Anne decide what amount of calories she needs to take in each day to achieve her goal of weight loss? Self monitoring is the key here if Anne decides she wants to go down the path of calorie counting.

Please see the following steps that Anne needs to complete:

Step 1: Download the MyNetDiary app (or another similar calorie counting app) and input daily food intake. This will give  a calorie intake value for each day.

Step 2: Check weight at the start of the week.

Step 3: At the end of the week using the MyNetDiary app total the daily calorie intake and get the average for the week (i.e. add up each day and divide by 7).

Step 4: Check weight again at the end of the week.

Step 5: Assess weight outcomes. If weight gain – Anne needs to reduce her daily calorie intake by at least 100kcals per day. If weight maintenance – Anne needs to acknowledge the benefit of weight maintenance but as weight loss is her goal she now needs to reduce her daily calorie intake the next week by 100kcals per day. If weight loss – Anne now needs to look at what worked to lose this weight and ask herself if she can do the same again for the next week. Anne also needs to look at the rate of weight loss. Initial rapid weight loss in the first few weeks is acceptable but over time healthy sustainable weight loss is 0.5 – 1kg per week.

Step 6: So based on her weight outcomes (maintenance/loss/gain) for the week and based on her average weekly calorie intake as calculated using MyNetDiary or another similar app. Anne is now able to decide what her estimated daily calorie intake for weight loss should be. Here again we need to be mindful that this will still be an estimate and weight loss will be influenced by many factors including daily physical activity levels.

What should my macronutrient intake be? If you're trying to estimate the daily intake of each macronutrient, you need to take a few aspects into consideration. The first one is your required calorie intake. This value is different for each individual. As discussed it is based  on factors such as age, sex, weight, or activity level. Additionally, you need to adjust this value based on the target weight i.e. less in the case of planned weight loss.

Once you know the total number of calories you should consume each day, you can calculate how many of them should come from proteins, carbohydrates, and fats.

A healthy diet should have the following distribution of macronutrients:

• 10%-35% of all calories should come from proteins. A second recommendation, is consuming approximately 0.8 g of protein per kilogram of body weight per day. For most people this translates to having a cereal for breakfast, 75g tuna in a sandwich at lunch and 100g chicken with a dinner meal. There is no need to add in extra protein to the diet apart from that typically taken.

• 45%-65% of all calories should come from carbohydrates. Additionally, you should limit simple sugars (such as sweets or white bread) to no more than 10% of your diet. For most people this translates into having bread or cereal at breakfast and bread/potatoes/pasta/rice at the lunch and dinner meal.

• 20%-35% of all calories should come from fats. In the case of this macronutrient, it is essential to monitor the type of fats you consume. In general, you should minimize the amount of saturated fats (e.g., butter or cream) and trans fats (e.g., margarine) and use healthier unsaturated fat substitutes from sources such as nuts or avocados. You do not need to count here. This essentially translates into having oily fish once to twice weekly and including more nuts and seeds and avocado in your diet for the healthy fats. Try to boil or bake foods rather than frying and try to avoid high fat processed foods. 

Following those recommendations will allow you not only to maintain your weight and lose weight if desired, but, may also protect you from diabetes and cardiovascular disease!