To lose weight effectively and safely, people should aim to lose 1–2 pounds per week. This means that losing 20 pounds safely can take up to 10 weeks. Dietary and lifestyle changes can help with quick and safe weight loss.

To lose weight successfully, people will likely need to follow a healthy diet and get regular exercise. Some popular diets are effective initially but may be challenging to maintain long-term. Individuals should personalize approaches to losing weight and consider their needs and lifestyle.

This article looks at what scientific studies suggest about how to lose weight successfully and safely. Using these tips may help someone lose 20 pounds or achieve their target weight, whatever that is.

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More than 1 in 3 adults in the United States are overweight or have obesity. Experts agree that being overweight increases the risk of health conditions, including heart disease, diabetes, and high blood pressure.

To assess if they are overweight, a person can measure their waist circumference and calculate their body mass index (BMI). They can find out how much weight they need to lose to stay in healthy parameters.

According to the National Heart, Lung, and Blood Institute (NHLBI), people should initially aim to reduce their body weight by 10%. A sensible approach is to lose 1 to 2 pounds per week for 6 months. After that, someone can base their weight loss strategy on the results they have achieved.

If someone has a lot of weight to lose, it may be wise to consult a doctor or registered dietitian to help them plan the best way to do this safely.

There are several diet and lifestyle approaches to losing weight. The following are tips that experts recognize as safe and effective ways to lose weight.

The NHLBI suggest a person should reduce their daily calories by 500–1000 calories a day to lose weight.

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) offer a Body Weight Planner to help someone make a personalized calorie and activity plan.

Experts devised the planner according to how diet and exercise quantitatively influence someone’s weight and help them maintain weight loss.

Being mindful of portion size can help someone reduce their overall calorie intake. Eating mindfully and appreciating tastes and textures can help people reduce overeating. Avoiding eating meals in front of the TV or on the go can also help.

Research suggests eating refined carbohydrates is associated with increased adiposity, insulin resistance, and obesity.

Refined carbohydrates include foods made from white flour, such as white bread and pasta, pastries, and baked goods. To try and lose weight, people should consider choosing whole grain versions of carbohydrates and limiting their portion size.

The Dietary Guidelines for Americans advise people to limit added sugars to less than 10% of their daily calories. Processed foods, sweetened drinks, and sauces often contain added sugars.

A 2015 review indicates that higher-protein diets are beneficial for weight loss and satiety. The review suggests that the quantity of protein necessary to promote improved weight management is between 89–119 grams daily for women and 104–138 g daily for men.

Protein foods include:

  • lean meat and poultry
  • fish and seafood
  • beans, lentils, and legumes
  • tofu and plant-based proteins
  • eggs and dairy products

A 2015 study indicates that reducing fats in the diet does not lead to more weight loss. The study also suggests that people eating a higher percentage of fats had slightly greater weight loss and better adherence compared to other diets.

Another study indicates that people on weight loss diets that permit nuts, which contain healthy fats, lose more weight and comply better.

Including smaller portions of healthful fats may help someone feel satisfied while they are losing weight. Doing this could help them avoid the temptation of sweet foods or refined carbohydrates. Healthy fats include:

  • extra virgin olive oil
  • olives
  • oily fish such as salmon, sardines, and mackerel
  • avocado
  • unsalted and unflavored nuts such as almonds, walnuts, and Brazil nuts
  • seeds such as sunflower, hemp, pumpkin, and sesame seeds

Research suggests that people can maintain their weight loss by increasing fruit and vegetable consumption.

Data from three ongoing prospective cohort studies in the United States suggests that plant-based diets are associated with less weight gain over 4 years.

However, according to the study, an unhealthy plant-based diet does not have the same effect. The emphasis should be on whole foods that contain fiber. Fiber can positively affect satiety and the gut microbiome, leading to less adiposity, according to the study.

Including more plant-based foods such as vegetables, fruits, and whole grains may help someone achieve their weight loss goals. People should try to avoid processed plant-based foods, as these can contain added sugars and unhealthy fats.

A 2017 review concluded that consistently performing exercise for longer than the basic recommendations for health (150 min/week of moderate-intensity exercise) does appear to be more likely to contribute to weight loss and weight maintenance efforts over the long term.

However, the same review recognized that variations in diet, BMI, and sex make conclusive recommendations more difficult. The study found that all types of exercise resulted in multiple health benefits for people with type 2 diabetes.

Another 2019 systematic review found strong evidence that people can maintain weight loss by increasing physical activity.

People should do exercise that they enjoy and try different types to see what suits them. Types of activity could include walking or running, strength training, or yoga. Some people may prefer gym classes or team sports, and others may choose to follow instructions on a video class at home.

Research suggests that reduced sleep may lead to overeating and increased abdominal fat. Scientists believe short sleep duration over-activates the body’s stress responses, which may lead to weight gain.

People can try having a regular bedtime routine to promote sleep in the evening. Strategies such as avoiding screens, sleeping in a dark and quiet room, or exercising during the day may work for some people.

A study in Obesity Reviews concluded that the adverse effects of stress can influence weight gain and abdominal obesity. The research indicates that improving nutritional status and sleep can counteract some of the impacts of stress.

According to the authors, during stressful times, someone may have increased needs for individual nutrients, including B vitamins and omega-3 fatty acids.

Along with improving their nutrient intake and sleep, people can try meditation, mindfulness, and yoga for stress relief. If a person has severe stress or trauma, they should see their doctor or consult a psychological practitioner.

A 2019 systematic review concluded that behavior change techniques such as self‐monitoring are key to maintaining weight loss.

Making themselves accountable can help someone to manage their weight. Having an exercise buddy or using food and exercise apps can also help. Keeping a food journal and regularly recording meals and weight may also be useful.

There are several strategies people can use to approach losing 20 pounds. To lose weight effectively and safely, people should aim to lose 1–2 pounds per week, helping them maintain their weight loss.

Having a healthy diet that includes plant foods, protein, and healthful fats can help someone lose weight successfully. People should also pay attention to their calorie intake and physical activity. Reducing stress and getting a good night’s sleep are essential too.