How Fast Can an Obese Person Lose Weight? The Ultimate Guide

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The odds seem to be stacked against those with obesity when it comes to obtaining a healthy BMI, or body mass index.

A recent study out of the United Kingdom, from the American Journal of Public Health, highlights this reality. This study tracking body weight surmised a decade’s worth of research, measured across 278,982 people. The study found the ability to lose weight was directly correlated to the current weight of the person. 

Studies show only one in 100 people with obesity will reach a healthy BMI again. Though it may be more difficult for them to maintain weight loss, those who are obese may lose weight more rapidly once engaged in physical activity or diet.

So, how fast can an obese person lose weight? Well, we should instead be asking how to maintain healthy body mass amid daily life and food cravings. 

How Much Weight Is Safe to Lose Per Week?

If you take a look around the internet for advice on healthy weight loss, you’ll typically see it’s safe to lose ½ to one pound per week. If you were to amplify this to two pounds per week, you would be looking at consuming a deficit of 1,000 calories per day. Unless cleared by a physician, this could be dangerous to your health.

Shedding pounds too quickly can leave people with stretch marks, extra skin, and rapid fluctuations in weight gain as soon as they significantly alter their diet. 

One pound per week for weight loss is considered a “gold standard” of sorts – it’s more easily attainable and can be sustained more effectively than drastically cutting weight. 

One pound of fat contains 3,500 calories. This means to lose one pound per week, you would need to be eating at a deficit of 500 calories per day. This is much more realistic than suddenly cutting out 1,000 calories from your diet, especially when your body would not be used to such a dramatic cut. 

Of course, for many people, this may seem too slow. If you have 100 pounds to lose, this method of weight loss could seem like a losing battle. 

However, for those who are obese or have a lot of excess weight, weight loss can be slightly accelerated. Men with 25% or greater body fat percentage, or women with 35% or greater, might be able to lose weight more quickly. If you’re strict with prioritizing healthy foods and don’t have any preexisting medical conditions, you can probably safely lose 3 – 4 pounds per week. 

What Is Unsafe Weight Loss?

obese woman with flabby arm on pink background

There is, without question, such a thing as unsafe weight loss. Generally, the main problem obese people run into when heavily restricting calories is nutrient deficiencies

Those who are already obese are likely eating low-nutrient foods. When a nutrient-poor food intake is reduced further, the consumption of essential fatty acids and minerals drops down below the requirements to sustain a body. This is a particular concern when it comes to electrolytes like sodium, potassium, and magnesium. 

Therefore, we can label unsafe weight loss diets as those that heavily restrict food intake to the point where you’re not able to get all the nutrients you need.

The solution to this is to ensure your diet is packed with nutrient-dense food choices, which come with their own health benefits.

The vast majority of calories should be coming from whole food that’s minimally processed. This means vegetables, fruits, lean meat and seafood, nuts, seeds, whole grains, and legumes. 

Most people would find it hard to overeat on foods like these, which often are high in fiber. However, when opting for healthy foods over processed or pre-packaged foods, you’ll more easily be able to meet your daily nutritional needs, while only consuming a small number of total calories. 

If you’re eating 1,200 – 1,500 calories a day, ensure this is coming from high-quality foods. The more restrictive the number of calories, the less room there is for treats or cheat meals. 

How Fast Can An Obese Person Lose Weight? 

One common diet mistake is to fixate solely on losing weight, rather than considering you don’t want to lose muscle mass. This is how people end up “skinny fat,” particularly in cases of rapid weight loss. You want to ensure you keep muscle loss to the absolute minimum during the entire weight-loss process. 

More muscle in proportion to body fat percentage means better overall health and longevity, and points to fewer markers of cardiovascular disease. This study out of McMaster University seems to reinforce this belief, proposing that a 40 percent calorie deficit over six weeks (involving intense training) resulted in little loss of lean muscle mass. 

Remember, the leaner you are, the slower your rate of weight loss should be to prevent muscle wasting.

How Much Weight Can An Obese Person Safely Lose?

If you want to lose weight as fast as possible without risking muscle loss, as an obese person, you should follow a diet that restricts calories to a 40 percent deficit. 

Although many suggest that quick weight loss can be dangerous, this is not an inherently true statement. The reality is, safe weight loss means you’re supplying yourself with enough electrolytes in comparison to your activity level. You must steadily increase your level of activity, hit all your essential nutrients, and eat unprocessed whole foods. 

Pay attention to muscle loss, which can easily be reduced by curbing the number of calories you eat. Ensure you intake a high amount of protein, and begin an appropriate level of physical activity. 

Even for someone who has the primary goal of losing weight, losing a lot of muscle will have you looking unhealthy and frail.

A man or woman with higher than 35 percent body fat can still safely lose up to four pounds per week, without worrying about extreme muscle loss or damage to the metabolism. 

As one study points out, even “5% weight loss may significantly improve the health of an overweight … individual besides reducing the risks for cardiovascular disease, diabetes, etc.” 

While we recommend you speak to your doctor for the best weight loss or diet program for you, weight loss itself is clinically recommended to help prevent metabolic damage and extra weight regain in patients. 


When we ask, “how fast can an obese person lose weight,” we tend to think in terms of diet and strict exercise programs, but we should remember what works for someone else may not work for us. While everyone’s body is different, it may be true that overweight people may find they lose weight faster, because of their body composition and higher body mass index. 

Weight regain can be a problem for some, it requires continual effort for anyone to maintain lost weight. 

If you have any questions about diet plans or other methods to ensure a weight loss plan is right for you, we recommend going to a doctor, who can also make sure underlying health conditions are addressed. A nutritionist can help you start a sustainable diet goal that emphasizes whole food like nuts, seeds, vegetables, and seafood. 

We’re here for you on your weight loss journey – check out our informational articles on having pride for the skin you’re in

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