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Weight Loss Expectations and Understanding Body Weight

What is body weight? 

Body weight is exactly as described – it includes the weight of all your bones, organs, body water, muscle mass and fat mass and more! 

Why do we use body weight to track body fat?

Measuring body weight is a relatively quick and easy way to understand how the amount of fat in your body changes over time. However, many other things can affect the number that you see on the scales.

What else affects body weight?

Our body weight is not only affected by the changes in amount of fat in your body. There are many other things which affect our scale measurements: 

  • Hydration – when we are well hydrated, we weigh more
  • Muscle mass – as we build healthy muscle in the body, we weight more
  • The menstrual cycle – women can experience more fluid retention in their body around the time of their period, increasing body weight for a few days
  • Our bowel contents – eating a large meal, or constipation, can increase our body weight as the extra food rests in our digestive tract.

Always remember that a small increase in scale weight due to some of these changes may reflect healthier change! You may have built more muscle mass or be more hydrated. So, it is important not to be disheartened by small fluctuations on the scale.

How often should I weigh myself?

Weighing your body every single day may not give the best picture of your progress. Many of the factors above can create small fluctuations in body weight, which could make you feel demotivated – especially when you’ve been trying so hard! We believe that weighing once a week, or once every two weeks, is a better way to track your weight. 

How much weight should I expect to lose? 

The total amount of weight that you can expect to lose after surgery, and your rate of weight loss, depends on the procedure you have chosen, how far along your journey you are, as well some other important factors… 

Gastric Bypass and Sleeve

In the first two weeks following surgery, some patients can lose a little weight. This is due to the liquid diet being low in calories and fibre. From week three, your body may spend some time healing and replenishing stores creating a stall in body weight. Some patients may even experience a small increase in weight at this point. These effects occur because your body begins to store more nutrients (e.g., glucose and water). A slower rate of weight loss at the early stages is usual and expected – it is actually a sign that you are making good progress by providing the body with the nutrients it needs. Following this, gastric bypass and sleeve patients can lose up to 1.5 kg (3lb) per week in the initial stages after surgery. This tends to slow to 0.5 – 1 kg (1 – 2 lb) per week by 6 months after surgery. Most weight loss following a gastric bypass or sleeve occurs in the first 18 months. 

Average weight loss after three years is:

  • 55 - 70% of your excess weight* with a gastric bypass
  • 55 - 60% of your excess weight* with a gastric sleeve

Gastric Band

Some (but not all) patients find they lose some weight in the first two weeks post-surgery, this is due to the liquid diet being low in calories and fibre. There may also be some swelling around the area that your band was fitted, so you may experience a little restriction when eating and reduced appetite. In the following weeks, you may experience a stall in body weight, some patients may even experience a small increase in weight. This is usual and expected and occurs because as you progress on to solid foods, your body begins to store more nutrients (e.g., glucose, water and fibre).

Within the first one to five weeks, any swelling around the band area can subside, resulting in a return of your appetite. In addition, you will not have had any band fills yet, so you may not feel much restriction when eating – your portion sizes may not be much smaller, you may still be feeling hungry between meals, and you still want to graze/snack through the day. This often called the ‘Yellow Zone’ and is all very usual for a band in the early stages – you are not alone. After five weeks, you may be making regular nurse appointments for band fills. With each fill you may start to feel a little more restriction and a reduction in your appetite and portion sizes.

The aim of band fills is to find your optimal band restriction (often called the ‘Green Zone’). Once your band is optimally adjusted, alongside healthy food choices and with the correct eating technique, you could expect to stay satisfied for 4-6 hours after eating 3 smaller portions of food per day. This can help you to eat fewer calories and lose weight. As a result, some people can lose 0.5 – 1 kg (1 to 2 lb) a week, although everyone is different. 

On average, patients lose 44 – 55% of their excess weight* during the 3 years following gastric banding surgery. You may find that you lose most weight in the first year following surgery.

Gastric Balloon

Across the 16 weeks, when compared with intensive weight loss strategies, having a Balloon leads to nearly 2.5 times more weight loss than undertaking intensive weight loss strategies alone – you will feel less hungry and feel fuller more quickly. With the correct dietary and lifestyle choices, you can be expected to lose 0.5 – 1kg/week (1 - 2 lb) whilst the balloon is in place.  On average, patients lose 15 – 20% of their total body weight over the 16 weeks that the balloon is in place. After the balloon is passed, patients should continue with smaller portions of food and any positive new habits to maintain or continue their weight loss. 

Why do some people seem to lose weight faster than others?

As described above, larger bodies will typically lose weight faster than smaller bodies. People with more weight to lose typically see a greater week-by-week loss - especially initially after surgery. Eating healthily, whilst limiting high calorie foods and drinks, alongside regular exercise will help you to lose weight at a quicker rate. In addition, muscle mass is more ‘metabolically active’ compared to fat mass (it burns more calories). Men naturally have more muscle mass, and therefore naturally burn more calories and can lose weight quicker compared to women. This is why building muscle through weight training is an excellent way to give your weight loss an extra boost, whatever your gender! Also keep in mind that muscle weights more than fat, so it's always good to try monitor your fat mass and muscle mass at the gym. 

Considerations for weighing your body:

If you can, try to keep your body measurements consistent – always weigh:

  • At the same time of day
  • Using the same set of scales
  • Before eating and after using the toilet
  • In light clothing and without shoes

What else can I measure? 

There are a number of different measurements you could make besides body weight. Sometimes, your weight loss may slow, but you could be losing inches!

You could track: 

  • Your dress size and how well your clothes fit
  • Waist circumference
  • Leg or arm circumference
  • Progress photographs
  • Waist-Hip-Ratio

If measurements or scale weight is not your thing, you could even track things such as your confidence or feelings of wellbeing! Sometimes holding onto others compliments can help as we often don’t register the change in ourselves that others can see quite easily! 

What should I do if my weight loss stalls?

  • To get the best results from your surgery it important to eat healthily whilst limiting high calorie foods and alcohol
  • Reflect on your lifestyle. Is there anything you can work on? Improving sleep quality, reducing stress, monitoring portion size, improving healthy snacking, increasing your daily movement… any of these things may be affecting your end goal of fat loss.
  • Mix up your exercise routine – doing so will keep it interesting and gives your body some variety of movement keeping the calorie burning efficient. You could try swimming, walking, jogging, joining a club or trying a new sport
  • Resistance training – building muscle through weight training is an excellent way to keep metabolically healthy and keep the calories burning. Remember that if you are keeping active your body may be building muscle– your scale weight may not reflect your progress!
  • Book an appointment with your dietitian or nutrition advisor. They are there to assess your diet and activity levels and give you a dose of motivation to keep going!

The most important thing is to not feel disheartened by a stall in weight and always remember how far you’ve come. Surgery is not a quick fix - the most sustainable weight loss occurs gradually over a longer period of time. Try not to compare your progress to anybody else - this journey is yours!

* What do we mean by the term ‘excess weight’?

Professionals can use the term ‘excess weight loss’ as a measure of your progress following surgery – excess weight is any weight which takes you above a healthy BMI. 

A healthy BMI is 25 kg/m2. Your weight at a healthy BMI is called ideal weight.  

You can work out your ideal weight by multiplying your height by itself (e.g., a height of 1.65m x 1.65m = 2.7225) and then multiplying this number by 25 (e.g., 2.7225 x 25 = 68 kg). 

You can work out how much excess weight you have by subtracting your ideal weight (kg) from your pre-surgery weight (kg). 

If you would like any help with these calculations, please talk to your dietitian/nutrition advisor in your next appointment. 

Transform Healthcare Limited is registered with the Care Quality Commission. Cosmetic surgery results and benefits can vary and are different for each individual. As such, Transform Healthcare Limited cannot guarantee specific results. Transform is a trading name of Transform Healthcare Limited, registered in England and Wales, Company Registration Number – 10616065. TRANSFORM HEALTHCARE HOLDINGS LIMITED is an Appointed Representative of Funding Falcon Ltd which is Authorised and Regulated by the Financial Conduct Authority. TRANSFORM HEALTHCARE HOLDINGS LIMITED (FRN:988595) has been added as an Appointed Representative under Funding Falcon Ltd (FRN:743100). Effective date: 29/11/2022

Transform Healthcare Limited is registered at, 132 Manchester Road, Rochdale, Greater Manchester, England, OL11 4JQ