Weight Loss Treatment

Weight gain can be caused by a number of factors pertaining to an individual’s age, hormones, nutritional choices and lifestyle:

• Ageing causes a progressive reduction in muscle tissue and strength due to factors such as a decrease in the body’s levels of growth hormones and a natural reduction in the ability of muscle cells to synthesise proteins into amino acids to build muscle. This mechanism causes an individual’s muscle mass to decrease as they grow older, resulting in slower metabolism due to the fact that muscle maintenance requires substantial energy expenditure. This reduction in metabolism makes it harder to expend calories at rest, causing weight gain.

  For more information, refer to our guide on 5 Reasons We Gain Weight With Age.

• Hormones can affect various physical functions that contribute to weight gain, including appetite, satiety (the feeling of being full), body fat distribution, cravings for high-calorie foods and overall metabolism.

  For example, ghrelin is known as the ‘hunger hormone’ because it signals hunger to the brain, while leptin signals to the body when to stop eating due to being full. Changes in the body’s levels of these hormones can increase an individual’s overall food intake as they feel hungrier than usual and do not feel as full despite eating. The combination of these mechanisms can contribute to weight gain.

  Insulin can also cause weight gain due to its role in regulating blood glucose levels by facilitating the uptake of glucose into cells for energy or storage. If insulin levels are improperly managed, glucose remains in the bloodstream, leading to elevated blood sugar levels and prompting the body to store excess glucose as fat.

  In women, changes in the body’s levels of the female hormones oestrogen and progesterone, such as during menopause, can influence body fat distribution and fluid retention, increasing the probability of gaining weight.

  On the other hand, men experience a gradual decline in the body’s levels of the male hormone testosterone which is required for muscle maintenance. This results in a decrease in muscle mass, slowing down the rate at which the body can expend calories, contributing to weight gain.

• Nutritional choices can cause weight gain if more calories are consumed than expended, causing the additional energy to be stored in the form of body fat. It is therefore advisable to eat a balanced diet consisting of protein-rich foods, such as eggs and lean cuts of meat, as well as high-fibre foods, such as fruits and vegetables.

  It is also advisable to eat more complex carbohydrates, such as whole grains, and fewer refined carbohydrates, such as sugar, to help slow down the release of glucose into the bloodstream. This can help prevent a spike in hormones such as insulin that increase fat accumulation and subsequently result in weight gain.

• Lifestyle choices can affect the total number of calories taken through food each day as well as the rate at which the body expends calories. For instance, alcohol increases appetite (particularly for high-calorie foods such as fried foods), and most alcoholic drinks contain a high number of calories. Therefore, excessive alcohol consumption can cause weight gain. Conversely, daily exercise, which includes the number of steps walked each day, can determine how many calories are expended by the body. Therefore, infrequent exercise increases the probability of gaining weight.

Obesity is a chronic disease which refers to the excessive accumulation of body fat and can result in an increased risk of developing serious health conditions. According to the NHS, obesity is diagnosed if an individual has a body mass index (BMI) exceeding 30. In comparison, individuals are deemed overweight for their height if their BMI is between 25 and 29.9.

Being overweight also refers to having an above-average weight due to excessive body fat. However, the excess weight can be managed through lifestyle adjustments such as dietary changes.

Individuals with a BMI between 18.5 and 24.9 are considered to be at a healthy weight, and those with a BMI under 18.5 are considered underweight.

Obesity can lead to a number of health risks, including:

• Cardiovascular issues (such as heart disease) - the accumulation of visceral fat around the organs can increase the volume of fatty deposits in the arteries (atherosclerosis), narrowing the arteries and increasing the individual’s blood pressure, which can cause an individual to develop cardiovascular issues.
• Joint pain - the high overall body weight of obese individuals can place additional stress on the joints in the knees, hips and lower back, accelerating the wearing of joint cartilage can result in substantial pain and discomfort.
• Respiratory issues - excess fat on the abdomen can restrict the movement of the diaphragm and compress the lungs, causing respiratory issues such as sleep apnoea and intermittent breathlessness.
• Type 2 diabetes - the accumulation of visceral fat on the body can cause fat cells to release inflammatory chemicals that affect the body’s ability to respond to insulin, resulting in elevated blood glucose levels, which contributes to the risk of developing type 2 diabetes.

The rate at which an individual loses weight depends on the size of the caloric deficit they maintain each day, as determined by their diet, lifestyle, and the use of weight loss treatments.

According to studies, a deficit of 500 calories per day results in approximately 1.1 pounds (0.5kg) of weight loss per week. This calorie deficit can be maintained by following a calorie-restricted but healthy and balanced diet, in addition to engaging in daily physical activity.

Additionally, using weight loss treatments can help maintain a calorie deficit and reduce the time it may take to see weight loss. For instance, injectable weight loss treatments such as Wegovy and Mounjaro contain active ingredients that aid weight loss by helping control appetite, slowing down gastric emptying to make you feel fuller for longer and stimulating insulin release after meals to reduce food cravings.

Furthermore, weight loss treatments are also available in the form of oral capsules such as Orlistat, Orlos, Alli and Xenical that help reduce the amount of fat absorbed by the body, which in turn reduces the total number of calories consumed, resulting in weight loss.

Whether the individual uses oral or injectable weight loss treatments, the rate of weight loss is faster if the daily caloric deficit is larger. With that said, it is not advisable to maintain a caloric deficit exceeding 500 calories per day without consulting a pharmacist or GP.

Weight loss progress can stall due to various factors:

• Low protein intake - Protein-rich foods such as eggs, red meat and nuts increase the body’s metabolic rate because more energy is required to break down protein compared to carbohydrates and fats. Therefore, low protein intake implies fewer calories are expended at rest, stalling weight loss.
• Skipping meals - Skipping a meal can cause a sudden drop in blood sugar levels, triggering the release of a hormone known as ghrelin, which can overstimulate the individual’s appetite. Skipping a meal can also cause the brain to seek out immediate energy sources, resulting in cravings for high-calorie foods such as sugar, which can stall weight loss.
• Irregular sleep schedule - Sleep deprivation caused by an irregular sleep schedule can hinder weight loss, causing increased fatigue and reducing the motivation to be physically active. Moreover, insufficient sleep can disrupt the balance of ghrelin and leptin hormones, which help regulate appetite and satiety. This can stall weight loss as the individual is more likely to eat excessively.
• Forgetting to account for changes to daily caloric requirements - As an individual loses weight, the number of calories they must eat to sustain weight loss decreases. If the daily diet is not adjusted to account for this change in caloric requirements, weight loss can stall.

For more information, please read our comprehensive guide on Why Weight Loss Can Take Time.

The most effective weight loss treatment differs for each person, and no single approach works for everyone. Factors such as age, underlying health conditions, diets and lifestyle habits can affect the suitability of and response to different weight loss treatments.

If you’re unsure which weight loss treatment to take, please complete our free online consultation for weight loss treatment to determine the most suitable option for you.

Weight loss capsules are formulated to be taken orally, while weight loss injections are formulated to be injected into the upper legs, stomach area (abdomen) or upper arms.

Moreover, weight loss capsules and injections have differing mechanisms of action depending on the active ingredient.

At Pharmica, we provide various brands and types of weight loss capsules to eligible patients following the completion of our free online weight loss consultation:

• Orlistat 120mg - a prescription weight loss aid suitable for adults with a BMI over 30. Orlistat is a dietary fat binder which blocks the lipase enzyme from breaking down and digesting fat molecules, causing fewer calories to be absorbed from the fat content of foods.
• Orlos (Orlistat 60mg) - a weight loss aid containing 60mg of the active ingredient, 'orlistat'. The lower dosage of orlistat in Orlos makes this treatment suitable for individuals with a BMI of 28 or above.
• Alli (Orlistat 60mg) - a branded version of Orlos which also contains 60mg of the active ingredient 'orlistat'. Alli and Orlos are medically identical and produce the same effects, however, Alli is more expensive than Orlos as it is a branded treatment.
• Xenical (Orlistat 120mg) - a branded version of the prescription weight loss treatment, Orlistat 120mg. Xenical and generic Orlistat 120mg are medically identical as they both contain 120mg of the active ingredient 'orlistat' and produce the same effects. However, Xenical is more expensive than Orlistat 120mg as it is a branded treatment.

We also provide injectable weight loss treatments with different active ingredients to eligible patients:

• Wegovy (Semaglutide) - a prescription-only weekly weight loss injection, which mimics a natural hormone called GLP-1 to reduce appetite, slow stomach emptying and increase feelings of fullness. The combination of these effects can help patients maintain a calorie deficit and aid weight loss when used alongside a reduced-calorie diet and increased physical activity.
• Mounjaro (Tirzepatide) - a prescription-only, dual-action weekly injection, which works by mimicking GLP-1 and GIP hormones to help control appetite, slowing gastric emptying to make you feel fuller for longer and stimulating insulin release after meals to reduce food cravings. Mounjaro should be used in combination with healthy lifestyle changes for best results.

Weight loss capsules containing the active ingredient ‘orlistat’ block the action of enzymes that break down fat in the digestive system. This results in approximately 25% to 30% of dietary fat passing through the body without being absorbed, helping achieve a caloric deficit to aid weight loss.

Weight loss injections work in various ways depending on the active ingredient. For instance, Wegovy contains the active ingredient ‘semaglutide’, which mimics the GLP-1 hormone to signal to the brain to increase the feeling of satiety and reduce hunger, making it easier to maintain a calorie deficit. Wegovy also slows down gastric emptying, keeping you fuller for longer.

In contrast, Mounjaro contains the active ingredient ‘tirzepatide’, which mimics the GIP hormone in addition to the GLP-1 hormone. This creates a dual-action effect that enhances appetite regulation, improves blood sugar control and slows gastric emptying to aid weight loss.

The number of calories an individual must consume daily to lose weight depends on their basal metabolic rate (BMR), which refers to the number of calories needed for vital functions, such as breathing and blood circulation.

BMR can be calculated using the Harris-Benedict equation and must be multiplied by an ‘activity factor’ to determine how many calories an individual should eat per day to maintain their current weight, known as their daily caloric requirement (DCR).

The number of calories required to lose weight is calculated by subtracting a certain number of calories from the individual’s DCR to create a caloric deficit.

For more detailed information, as well as examples, please refer to our expert guide on How To Achieve Weight Loss Goals In 2025.

Exercise is not strictly necessary for weight loss; however, it can significantly help in achieving and maintaining a calorie deficit.

Exercising can increase the rate at which the body expends calories. Moreover, certain exercises, such as weightlifting, can provide the added benefit of helping to build muscle and increase overall metabolism, since a higher number of calories is required to maintain muscle mass compared to fat mass.

It is recommended to exercise routinely (if possible) in addition to eating a balanced, calorie-restricted diet for healthy weight loss.

Recommended reading: Seven Scientifically Supported Weight Loss Strategies

According to the NHS, it is safe to lose approximately 0.5kg to 1kg of weight per week. This rate of weight loss maximises the probability of fat being lost as opposed to muscle, resulting in a better body composition.

Additionally, reducing one’s weight by a maximum of 1kg per week can help minimise the risk of experiencing nutritional deficiencies or other health issues arising from an excessive calorie deficit.