Weight management mechanics

Assuming you don’t have a psychological/emotional connection with food, weight management is simple.

That said, I think 87% of people I see have a psychological/emotional connection with food, so this technical rundown won’t really help, but eventually, you’ll end up needing these skills.

If you want to know is now is a good time to lose weight  try this questionnaire

If you need to know if your weight issues are emotionally driven,  try this questionnaire

To lose weight or manage your weight “ALL” you need to do is: 

a) Roughly work out what food your body needs to thrive and survive, and eat that amount.

b) To put weight on, add more food. To reduce your weight, eat less


To be able to apply these mechanics to your weight management goals, you need to complete several tasks (and sub tasks)


  1. Weigh yourself! 

 No weighing = no weight management


If you are not weighing, you are guessing

If you don’t have bathroom scales, go and get some. Successful weight managers check and monitor their weight at least once a week. 

Some can find this difficult. Some people start weighing every hour and become compulsive. So try not to go too mad.

But you have to confront and understand where you are. So yes to weekly weighing. Personally I think 2-3 times a week is fine.

Weigh yourself and write the figure down.

If you cannot do this, the chances are you have a psychological issue, see if this questionnaire helps try this questionnaire


2) Measure your height

You need to know your height. Some assessments also use your neck, waist and wrist measurements, so there are lots of uses to justify owning a tape measure.

Buy or steal a scale and tape measure.

Now, using this information, work out how many calories you need to eat. For now, don’t stress, a calorie is simply a measure of food)

3)  Calculate the amount of food, or calories you need to eat.

Now, using the information (weight and height) work out how many calories you need to eat.

Simply visit any or all of the calculators below , and get a rough idea of what you need to stay as you are, and what you need to lose weight

Try this one


Or this one


If Googling is to your taste, you can have a feast looking for these calculators.

They may make different assumptions, so feel free to average a few of the readings, or decide one is correct and use that.

Write your figures here

To stay as I am, I need to eat………… calories

To lose weight, I need to eat ………….calories

If you want to understand how these calculators are made, look at appendix 1

4)  Monitor and measure the food you eat and drink

So, what do we put in our mouths?

Basically it’s carbohydrates, fats and protein. A good diet has a mix of these.

To successfully manage your weight, you need to weigh and measure food and drink, so you need to 

5) Buy a kitchen scale and a set of measuring cups and spoons.

Using the scale, simply weigh your food in grams. Then use the internet, Google or an old fashioned book, to calculate the calorie value.

All you need to know is that calories are expressed as kcal.

Now  record it in a food diary


The food diary isn’t just a dull boring record of what you ate and its calories content. 

It will become a live document giving you lots of insight into how you eat and what effects it.

It could be very easy to make weight loss about eating the most restrictive miserable diet, and obsess about figures. Weight loss is about  you understanding you.

So by each meal, you need to have these boxes

Score your Hunger before eating  (0=not hungry, 10= starving)

What did you want to eat (were you after an ice cream and settled for an apple?)

Your mood (happy, sad, bored?)

Where did you eat ( was it scoffed down at your work desk or did you eat it at a dining table)

Speed of eating (savoured or stuffed down: some count Chews per mouthful)

Full or  satisfied

Was the meal balanced, (say 40% carb, 30% fat 30% protein)


  1. According to the NHS

“As a guide, an average man needs around 2,500kcal a day to maintain a healthy body weight.

For an average woman, that figure is around 2,000kcal a day”

The good news is you don’t need to work on averages. Simply use the figure you worked out above, 

2) The rule of thumb is this that to lose 0.5kg ( or a 1lb) you need to reduce your calorie intake by 3500 calories


So  lets assume you need 2000 calories a day.  If you only eat 1500 a day, you are in a calorie deficit of 500 calories a day. If you did this for 7 days days ( 7 x 500=3500) you should  lose  0.5 kilo.

3) Exercise is ‘interesting”.

Most people exercise to be healthier or because they love being active.  You can lose weight simply by manipulating your diet. As a trainer I love exercise and being active can really help. 

However, there is a limit to how much you can change at anyone time.  

To decide to change your diet AND for example  get up early to go for a jog, can be a big ask. It’s also  possible to make yourself hungry by increased activity.

The reality is there are 2,  possibly 3 things you can do to lose weight.

  1. Reduce the amount of food you take in
  2. Increase the amount of exercise you do
  3. A mix of both.

This process is monitored through weekly self weighing ( or 2-3 times) and a detailed food diary.

What happens now is to try and achieve a calorie deficit.

The problems you will encounter are

  1. Overestimating the effect of exercise. The calorie meters on rowers and bikes are often  pure fantasy, but it’s a starting point. 
  2. Underestimating and guessing food. The moment you ask people to measure and record food is the moment they start guessing (the weight), and forgetting (to record)

You are now the experiment.

To lose weight you must take charge and take responsibility.

The process is to compare, and be guided by the results. If in a week’s time you think you ate 500 calories less each day, and you’ve done an extra 500 calories of exercise a day, that’s a theoretical deficit of 1000 a day, so each 7 days you should lose 1 kilo!

If not, be honest about your food recording.  If that’s 100% dialed in, you need to critically look at the exercise you are doing. Is it really 500 cals a day?

Within a month, if not a couple of weeks, you’ll be able to compare your results with your records and you’ll have a useful bit of evidence. Maybe you’ll know that if you eat 1600 cals a day, you’ll lose weight. You’ll possibly know that if you try and starve at 1300 calories, you go mad and eat high calorie foods.

Many people carefully, review their physical activity and make more modest assumptions

This is all you need to  know to lose weight.

Compare this to a household budget: you need to know your income and your outgoings. Without those two figures you are pretty doomed to failure! 

Imagine bringing in a financial consultant who told you these figures don’t matter!


Many people cannot control their food intake.

Some people are unable to exercise any restraint whatsoever! Maybe there is a deeply embedded psychological reason. Maybe there are impossible habits you have made between being happy and eating or being sad and eating. You may have convinced yourself there is some advantage to being overweight: ask yourself what they might be, and ask yourself “Is that really true?”

There could be barriers at home or work. You may be too busy to take anything else on at this time. Maybe your partner wants to keep you big, to keep you all to themselves.

So, maybe you need support from me , a group, or a friend. Some will find they need therapy or a councillor.

Unrealistic  goals

Most agree that 0.5-1kg a week is possible. Trying to go more than that is problematic

Lack of patience

It takes time to change your weight. Your body doesn’t care about that wedding or your outfit in 14 day!

Everything else is either tactics or politics.

There is a tactic where if you just eat protein, you fill up quickly and (hopefully) easily achieve a calorie deficit. If I allowed you to only eat chicken, (no batter, no bread, no vegetables, no nuts) you would struggle to achieve a calories intake.

Some diets suggest you only eat within an 8 hour window each day. 

The implication behind all these diets is that you can eat whatever you like (which is never true). The fad diet designers gamble on the fact that you will eat less. The mechanism they all have in common is still a calorie deficit!

People will hide “politics” or “idealism” in diet advice. Recommendations to do/don’t eat meat, eat clean, avoid wheat, boycott dairy are idealist positions. If you agree with them, fine, if not don’t get thrown off track. 

If you support these types of initiatives

Stumbling points

Soon, you’ll stumble across a smart ass trainer who tells you not to look at calories. theyw ill correctly point out that calories are inaccurate for a variety of reasons, like the ones below:

“[T]he ratio between the amount obtained by laboratory analysis and the amount declared on the product label in the Nutrition Facts panel must be 120% or less, i.e., the label is considered to be out of compliance if the nutrient content of a composite of the product is greater than 20% above the value declared on the label.”  (FDA Guidance for Industry: Nutrition Labeling Manual)

In summary, a calorie is not necessarily a calorie: given the functional differences between edible plants, interfamily and even interspecies differences must be considered when making comparisons between food processing techniques.  (Proc Natl Acad Sci, 2012)

There’s also good evidence that our gut health (and gut bacteria) plays a role in how many calories we absorb from our food. (Amer J Clin Nutr, 2011)

There is also a line of criticism that you bury yourself in a world of counting, and that you quickly ignore eating, and replace it with math sessions. Obviously, if you cannot use a measuring system without becoming obsessive, you need help, but calorie counting is the same as looking at price, using a clock,  using a ruler! 

The reality is that after a week, you see that you have regular foods, and you quickly get to know them. You need to recalibrate now and then (portion sizes escalate), but it becomes easy to adopt.

I should say that most wont even get this far as their emotions will undermine this, but its nice to know the system!

Appendix 1

How do you use energy (or how do clever people workout how many calories you need.)

If you want to “do a bit of science”, 

Because you think, breathe, repair skin and grow hair, you use energy all the time. This is known as the 

Basal metabolic rate BMR (lying there asleep)

As its difficult to get you to lie down and do nothing, people prefer to measure. 

Resting metabolic rate RMR.Its  an easier calculation as its you at normal rest,

Then you spend energy eating and digesting food. This known as the 

Thermic effect of food TEF  – the energy you spend consuming food (chewing to pooing)

Exercise activity ( jogging 5k, gym sessions)

Non-exercise activity thermogenesis NEAT, fidgeting, housework, punching your brother, worrying the cat.

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