It’s not a secret that the population of the United States has high levels of obesity. In 2012, Georgia attempted to raise awareness and thwart childhood obesity with shocking ads showing children with obesity with captions such as “It’s hard to be a little girl if you’re not,” and “Stop sugarcoating it, Georgia.”
The controversial ads had been based off of previous public health campaigns such as those aimed to prevent smoking and encourage quitting. However, the causes of obesity, its impacts on our health, and effectiveness of strategies for shedding pounds are not nearly as straightforward as putting down a pack of cigarettes.
Researchers have found that the ways our bodies store—and eventually burn—fat are more complex than we thought. Prevention of obesity requires a multifaceted approach that addresses not only calories eaten and burned, but consideration of genetics, hormones, chronic conditions, and side effects of medications. Here’s what you need to know.
Obesity Definition and BMI Measurement
First, it’s important to note that obesity and excess weight are things you have, not things you are. Obesity is a condition characterized by carrying extra weight on your body. Essentially, the Centers for Disease Control and Prevention (CDC) defines overweight and obesity as carrying more weight than has been deemed healthy for your height.
Overweight and obesity are measured using the body mass index (BMI) which is a calculation based on a ratio between your height and weight. There are cutoffs that designate whether you have too little weight, a normal weight, extra weight, or obesity. However, the measure is considered very simplistic, and doesn’t take into account the large amount of variability in how weight is distributed on different bodies. It doesn’t differentiate between fat mass and muscle mass, for example.
In June 2023, the American Medical Association (AMA) acknowledged that not only is BMI not sufficient for defining a healthy weight on its own—the organization suggested it should be used in conjunction with other measures such as waist circumference and genetic risk factors—but that when used on its own, it exacerbates ongoing disparities in healthcare. The model fails to take into account differences among genders, ethnicities, and ages.
Women carry more fat tissue than men. Black women tend to have more lean mass than white women, for example, and might be labeled as having obesity, even though the weight they’re carrying is healthy and is not increasing their risk of any disease. Asian women have the opposite problem; they have a higher risk of cardiovascular disease at the same BMI as white women.
What Causes Obesity?
The simple version is that when you consume more fuel (food and calories) than your body uses throughout the day, that fuel gets stored as fat cells. The more and larger fat cells you have, the more likely you are to carry excess weight. However, there are many factors that influence what we eat, how much we eat, how much energy we burn, how much we store as fatty tissue and where that fatty tissue lives in our bodies.
Top 6 Causes of Obesity
- Imbalance in diet and exercise
- Genetic predispositions
- Chronic conditions such as hormonal imbalances and mental health conditions
- Side effects of medications
- Lack of sleep
- Chronic stress
Is Obesity Genetic?
It’s not clear exactly how much of your risk for obesity is inherited. Twin studies in the early 2000s suggest it was 40-70% heritable. However, there are hundreds of genes that influence our risk of obesity. A small number of those genes can lead to severe, early onset obesity (before the age of 10). In most cases, a number of genes that all have a small impact combine to raise an individual’s risk of carrying extra weight.
Some of those genes influence our hormones. For example, one genetic mutation might make you produce less leptin, a hormone that tells your brain when you’re full, or make you less sensitive to the signals it sends. That could lead to you overeating without even realizing it. In many cases, a healthy diet and exercise can help reduce the impact of these genes on your weight and be a major player in the prevention of obesity.
Chronic Conditions, Hormones, and Obesity
As mentioned above, hormones—which are chemicals in our bodies that send messages that tell cells and tissues how to function—can influence our weight. Fat tissue itself can secrete hormones, such as leptin, the one that tells your brain you’ve had enough to eat. However, there are many conditions that can interrupt your normal hormonal signaling and raise the likelihood that you’ll gain weight.
Some conditions that can mess with your hormones be causes of obesity:
- Polycystic ovary syndrome (PCOS)
- Insomnia and sleep apnea
- Cushing’s disease
Many other conditions might indirectly be a cause of obesity. For example, any condition that leads to chronic pain might make it difficult for you to get the amount of exercise your body needs to maintain your weight.
One of the first things you should do if you start gaining weight, and you don’t know why, is to review any medications you’re currently taking with your healthcare provider, especially if any are new drugs or supplements you started in the past few months. Medications are one of the causes of obesity for many people.
Many drugs can cause weight gain, including:
- HIV medications
- Corticosteroids (often prescribed for autoimmune diseases)
Before starting any new medication, make sure you discuss the side effects with your healthcare provider, and ask questions about whether it’s likely to make you gain weight. If it is, but it still seems like your best option, make sure to ask what you can do to prevent obesity.
Environmental Exposures and Obesity
They’re not yet well understood, but scientists have linked being exposed to certain chemicals in the environment such as PFAS, to hormonal disruptions that can raise your risk for obesity.
Social Determinants of Obesity
Your access to affordable healthy food and safe spaces to get exercise inside and outside can make a big difference in your habits, and thus your weight. The people around you can make a big difference too. We tend to mirror the habits of the people we spend time with. For example, one study found that adolescents were more likely to have obesity if their family practiced unhealthy eating patterns.
Obesity Health Risks
There are many health risks associated with obesity, including:
- Heart disease
- Type 2 Diabetes
- Worsened COVID outcomes
- Sleep Apnea
The ways that obesity is linked to these conditions is not always clear. A September 2023 study found that a larger waist to hip ratio was associated with an increased risk of death, regardless of BMI, suggesting that the location of your excess fatty tissue is more important than how much of it you have, with fat located in the abdominal area being the most damaging to your health.
Obesity and Mental Health
While we may most commonly associate diagnoses like diabetes and hypertension with obesity, one 2023 study found that being diagnosed with obesity raised the risk that you’d be subsequently diagnosed with psychiatric conditions such as depression, anxiety, and personality disorders. The researchers hypothesized that the association may be due to multiple factors including higher levels of inflammation in the brain and lower quality of life. Maintaining your mental health is an important part of preventing obesity.
Obesity and Alcohol
The evidence is not completely clear, but alcohol does have calories, and experts believe that consuming alcohol, especially in large quantities (more than 1 drink a day for women and 2 for men) can contribute to weight gain. Alcohol may slow your fat metabolism and interfere with the hormones that tell your body you’re full. Additionally, carrying extra weight can amplify alcohol’s damaging effects on your liver.
Does Weight Loss Always Improve Health?
Given that having obesity is associated with so many risks, it should be safe to assume that if you carry any extra weight, losing it will automatically improve your health, but researchers say that this isn’t always the case. While the associations are true on a mass population level, they don’t always hold up for individuals. Some people who carry extra weight are already healthy, fit, and not showing any signs of increased disease risk, such as high cholesterol.
Additionally, in seniors, carrying a little weight can protect against injuries from falls and provide energy if they become sick.
It’s also difficult to tease apart the effect of actual weight loss from the effects of adopting healthy habits such as maintaining a Mediterranean Diet and increasing physical activity. In many cases, these habits improve your health even if you don’t lose weight.
For example, the Mediterranean Diet is associated with a lower risk of dementia, cardiovascular disease, cancer, chronic obstructive pulmonary disease, and Type 2 diabetes. Getting in your steps leads to less overall risk of death as well. Some doctors are advocating for healthcare professionals to avoid focusing on their patients’ sizes, and instead hone in on their health-promoting habits, regardless of their weight.
To advocate for your own health at any weight or to find a doctor who won’t focus on the number on the scale to the detriment of other signs of your health, check out these resources from Health at Every Size.
Diet, Exercise, and Mental Health
Whether it’s walking, yoga, or triathlon training, it’s well-known that exercise can strengthen our mental health along with our muscles; so can a healthy diet. Our brains and our guts are connected. Mediterranean and plant-based diets have both been shown to improve moods and even help reduce depression symptoms, whereas diets high in fat and sugar are linked to worsened memory and greater impulsivity.
Ways You Can Manage Obesity Without Drugs
Exercise for Weight Loss
There’s an age-old debate about how much exercise really helps with weight loss. Many believe if you exercise enough to burn more calories than you eat, you should automatically lose weight. Others say that the majority of weight loss takes place in the kitchen when we prepare meals with fewer calories. Exercise can, in fact, help with weight loss and the prevention of obesity, but it’s most effective when it’s higher intensity and it’s still paired with dietary changes, according to a review of 43 studies.
Does Exercise Make You Healthier Even if You Don’t Lose Weight?
In the same review mentioned above, exercise typically led to weight loss, as well as improvements in cardiovascular health. However, even when weight loss was minimal, exercise still improved health by lowering blood pressure, triglycerides, and glucose.
How to Start Exercise If You’re Overweight
Starting and maintaining a new exercise routine can be challenging whether you carry extra weight or not. Some of the most effective strategies for getting started include making a plan and choosing activities you enjoy. For example, if you hate running, don’t do it! Try going for walks, hiking, swimming, or joining an adult sports team. Inviting friends can help you stick to your plan.
If you carry extra weight, make sure to start slowly and gradually build up your routine to lower your risk of injuries or stressing your joints. Check out these resources for getting started.
Best Diets for Weight Loss
First and foremost, it’s important to note that, while we often refer to certain eating styles as “diets,” there’s a difference between crash diets for short-term weight loss, and eating habits you can maintain throughout the lifetime. In many cases, these shorter term diets will aid in short-term weight loss. The problem is that when you stop following them, you’ll not only gain weight back, you may end up carrying more weight than you did before.
At MedShadow, we often recommend the Mediterranean diet for lifelong health, as it’s one of the best studied, is not restrictive, and is associated with many benefits.
However, the diet you choose has to work for you, and may depend on your personal health goals. For example, if you have PCOS or insulin-resistant diabetes, a diet in which you get less than 45% of your calories from carbohydrates may be helpful for weight loss or the prevention of obesity. The popular keto diet, which is a very restrictive low-carbohydrate diet (less than 10% of your calories come from carbohydrates and most come from fats) can help you lose weight, but may be difficult to stick to, and is associated with some side effects such as elevated cholesterol.
Starting with a Whole 30 Diet can help you find foods that make you feel your best. You can use that month-long test to determine which foods to include in your diet long-term.
The healthiest diets will be those you can maintain long term, that help you lose weight gradually over time, at a rate of no more than one to two pounds per week. Any more than that and you raise the likelihood that you’ll soon plateau or gain the weight back, and possibly put yourself at risk for other conditions such as malnutrition or eating disorders.
Between 2007 and 2018, more adults aged 20 or older report being on a diet, with low calorie and low carbohydrate diets growing in popularity.
More research is needed, but restrictive dieting may raise your risk for developing eating disorders such as anorexia or orthorexia, an unhealthy and restrictive obsession with “clean” eating.
Former bride, Kelsey Herber details how a desire to lose weight before her wedding started with making a few healthier choices but soon escalated into a full-blown obsession over her weight, eating and exercise habits in The New York Times. The sheer idea of having pancakes with her friends sent her spiraling. When she got married, she enjoyed her wedding cake, and planned to take a break from her intense diet. But that just sent off a cycle of binge eating followed by restriction, also known as binge eating disorder.
Eating Disorders, a Risk of Restrictive Dieting
Having obesity raises the risk you’ll experience an eating disorder, especially if you’re younger. Nearly a quarter of children and adolescents display symptoms of disordered eating, according to a 2023 analysis of 32 studies. Eating disorders come in many forms. Two of the most well-known are anorexia, in which an individual severely limits their food intake and may weigh themselves repeatedly, and bulimia, which is characterized by a need to purge food by vomiting, exercising excessively, or using laxatives to induce excessive bowel movements.
Other eating disorders include binge eating disorder, in which you experience episodes of binge eating that are difficult to control. Between binges you may attempt to maintain extremely rigid and restrictive eating. During those episodes you might eat an entire loaf of bread, for example. A newer diagnosis is orthorexia, an excessive preoccupation with “clean” eating that causes restrictive eating patterns and serious distress, though not all experts agree on how to diagnose it.
These conditions can lead to malnutrition, brittle bones, dehydration and even death.
It’s important to note that being underweight is not a requirement to be diagnosed with an eating disorder. While we may imagine people with anorexia as being dangerously thin, for example, the condition can coexist with obesity. If you suspect you or your child may be developing characteristics of an eating disorder, discuss it with your healthcare provider so you can get treatment as soon as possible.
Eating Disorder Treatments include therapy, inpatient medical care, nutritional counseling, and possibly medications such as antidepressants.
Sleep and Weight Loss
After a night spent tossing and turning, hormones that control your appetite can get pushed out of whack. Your levels of leptin, the hormone that tells your brain you’re full, tends to be lower, and levels of ghrelin, a hormone that tells you you’re hungry are higher. Ghrelin levels after lack of sleep were even higher in people with obesity than those without. Good sleep is crucial to maintaining a healthy weight and preventing obesity.
Stress and Weight Gain
High stress affects all of us differently. Some of us can’t bear the thought of eating when we’re in stressful situations, whereas others find themselves gorging. But, when that brief stressor transitions to chronic daily stress, scientists have found that levels of cortisol, the stress hormone, are elevated, and that can lead to eating more. And the foods we tend to reach for under these conditions tend to be calorie-dense and less nutritious. High cortisol is also associated with more abdominal fat, meaning chronic stress can be one of the causes of obesity.
It’s important to know that when you have extra fatty tissue on your body, you might metabolize certain drugs differently, meaning they stay in your blood for a different amount of time or reach different concentrations than expected. You may need to discuss adjusting your doses with your healthcare provider.
How to Treat Childhood Obesity
Treating childhood obesity can feel like a balancing act. It’s crucial to help model healthy behaviors such as getting healthy foods and physical activities, but it’s often more important to help the child build self-esteem, and provide love and acceptance at any size.
Early dieting during childhood and adolescence can be a risk factor for developing obesity and eating disorders later on.
Regardless of whether or not a child loses weight, regular exercise can improve executive functions (things like making plans and managing behavior) and a healthy diet can improve overall school achievement, according to a review of 18 studies in children and teenagers with obesity.
In some circumstances, healthcare providers may recommend weight loss drugs such as Wegovy and Ozempic to teenagers. So far, research has shown the side effects of these drugs in teens are similar to those seen in adults, but that most people who take them have to take them for life. The long-term side effects of these drugs are not yet known as they are new to the market.
Why Is It Hard to Keep the Weight Off After Losing It?
When you lose weight, you experience all sorts of changes in your body such as differences in your metabolism and hormone function. Scientists are still teasing apart the effects of all of these changes, but they do know that the majority of people who lose weight eventually put most of it back on.
One study found that adults who had previously had obesity or were overweight but lost weight were more likely to keep that weight off after a year if they adhered to a Mediterranean Diet, rather than other types of diets. While what you eat seems to have a bigger impact on weight loss than exercise does, a consistently greater amount of exercise is likely to help you keep it off, according to a study of people who lost weight and kept it off for nine years. One way it may help is by increasing your sensitivity to leptin, the hormone that signals fullness, and reducing inflammation in your body.
Medications for Weight Loss and Their Side Effects
There are a handful of drugs currently approved for weight loss. Still, when Wegovy (semaglutide), a repurposed diabetes drug, hit the market in June 2021, it set off a frenzy. The drug is thought to cause more dramatic weight loss than its predecessors. Several more drugs are likely to be approved by the FDA soon. All of these drugs are meant to be used in conjunction with a healthy diet and regular exercise.
Rapid weight loss, regardless of the strategy used can cause:
- Muscle mass which fades along with the weight
- Sagging facial skin due to loss of fat. Fat keeps skin plumped and elastic
- Hair loss
Mounjaro (tirzepatide) is a diabetes drug. In November 2023, the FDA approved tirzepatide under the brand name “Zepbound” for weight loss. The injection mimics two hormones that reduce your appetite and make you eat less. The FDA listed several common side effects of Zepbound including:
- abdominal discomfort and pain
- injection site reactions
- hair loss
- gastroesophageal reflux disease.
The label also notes a possible risk of tumors seen in rats. It’s not yet known if the drug raises the risk of cancer in humans, but the label does warn that the drug should not be used in patients with a personal or family history of medullary thyroid cancer or in patients with Multiple Endocrine Neoplasia syndrome type 2.
This list of side effects is very similar to the early lists of side effects we saw with Wegovy (described below) upon approval. Since that drug has been on the market for two years, research has suggested several other risks such as suicidal thoughts, intestinal obstruction, and dehydration due to a lack of thirst. Given that the drug is so new, we are likely to learn more about how it affects our bodies as more and more people start to take it.
There aren’t many reported experiences from people who have used the drug for weight loss yet, but those who have taken Mounjaro for diabetes have reported weight loss, nausea and other common side effects listed above on AskAPatient.com
“Worked great on the beginning but increasing dosage caused nausea, vomiting and diarrhea that would keep me in bed for 2 days. Lost 20 pounds and A1c down significantly, but not sure it’s worth it” wrote one user.
Wegovy works by slowing your digestion and keeping you full for longer, so you eat much less than you typically would. While the drug was FDA approved under the brand name “Wegovy” for weight loss in 2021, it was previously approved for treating diabetes under the name “Ozempic.”
A Reuters investigation found 265 reports of suicidal behavior in individuals taking the drug sent to the FDA database, which regulatory agencies in the U.S. and Europe are now investigating.
Side effects such as nausea were severe enough that about 20% of participants dropped out of the trials. It is important to make sure you’re staying hydrated and consuming enough vitamins and minerals while taking Wegovy.
In both the adult and adolescent clinical trials, patients commonly reported the following side effects of Wegovy:
- Loss of interest in alcohol
- A possible increased risk of medullary thyroid cancer
- Intestinal obstruction
In November 2023, Novo Nordisk published results of a large trial (including over 17,000 participants) testing Wegovy on patients with excess weight and diagnosed heart disease, but who did not have diabetes. They found that the drug lowered the risk of cardiovascular events such as heart attacks, stroke, and deaths over the course of about five years. It’s important to note that the trial did not specify lifestyle changes such as diet or exercise for participants who took Wegovy or who took a placebo. About a third of patients in both the Wegovy group and the placebo group reported experiencing severe adverse events (mostly gastrointestinal side effects or gallbladder disorders), but only 8.2% of those in the placebo group dropped out of the trial because of them, compared to 16.2% of those who were taking Wegovy.
Saxenda is an injection that uses the active ingredient liraglutide. Similar to semaglutide, liraglutide was originally used to treat diabetes under the brand name Victoza. In 2014, the FDA approved a new formulation of it as Saxenda to treat obesity. It works by slowing your digestion and making you feel fuller.
Many of the side effects are similar to those of Wegovy. The side effects of Saxenda include:
- Inflammation of the stomach and intestines
- Low blood sugar
- Increased heart rate
- Kidney problems
Note: In the adolescents trial, one participant who was taking Saxenda ended his or her own life. The FDA’s 2020 approval of Saxenda for patients over the age of 12 recommended monitoring mental health.
Xenical, Alli (Orlistat)
Orlistat is an injection that works by lowering the amount of fat your intestines absorb from meals. On AskAPatient.com many patients describe oily stools and excessive gas or diarrhea, particularly after eating meals with more than 15 grams of fat.
Other side effects of orlistat include:
- Abdominal pain
- Anal fissures
- Liver problems
- Kidney problems
- Inability to absorb enough calcium or vitamin D
Orlistat also interacts with several other drugs. Be sure to discuss any drugs or supplements you take with your healthcare provider, but especially:
- Amiodarone for abnormal heart rhythms
- Cyclosporine, an immunosuppressant
- Levothyroxine for an underactive thyroid
- Antiviral medications
Imcivree is approved specifically for people with obesity who also have one of three specific rare genetic conditions. It helps their brains receive the signal that they are full.
- Depression and suicidal ideation
- Spontaneous penile erections
- Skin pigmentation
- Injection site reactions
- Abdominal or back pain
- Upper respiratory tract infections
Contrave is a pill that combines a drug that blocks opioids (naltrexone) and an antidepressant (buproprion). It’s believed to suppress appetite and cravings. In September 2020, the FDA sent Contrave’s manufacturer a warning letter for downplaying the drug’s serious risks—such as suicidal ideation—in its advertisements.
Side effects of Contrave include:
- Suicidal thoughts and behaviors
- Psychiatric changes such as hallucinations and depression
- Increased blood pressure and heart rate
- Liver problems
It interacts with many other drugs, be sure to discuss any treatments or supplements with your healthcare provider.
The drug works by lowering your appetite and making you feel more full. Topiramate is an anti-epileptic drug, which has been repurposed and sometimes prescribed off-label for a variety of indications including migraines and depression.
Qsymia can cause birth defects such as cleft lip and palate if taken while pregnant. Make sure to take a pregnancy test before starting Qsymia, and use contraception while you take it.
Side effects of Qsymia include:
- Suicidal ideation and behaviors
- Mood changes such as depression
- Slowed growth in adolescents
- Kidney problems
- Joint pain
- Pins-and-needles sensations
- Changes in taste
- Dry mouth
Surgery for Weight Loss
Some people with obesity undergo bariatric surgeries, such as getting a gastric sleeve or gastric bypass. These surgeries tend to be more effective than diet and exercise alone. Surgery, in general, comes with increased risks such as surgical and anesthetic complications. Read more about weight loss surgeries here.
Supplements for Weight Loss
Before you consider taking any supplements to help with weight loss, bear in mind that, while any supplement can be contaminated or contain substances other than the label suggests, those marketing for weight loss are some of the worst offenders. One way to reduce your risk is to check the label for a certification that the supplement has been tested by a third party. Groups like the National Science Foundation (NSF) or the United States Pharmacopeia (USP) test supplements to confirm that they contain the products listed on the label and don’t have unsafe levels of contaminants.
Berberine for Weight Loss
Berberine has been referred to as “nature’s Ozempic.” It’s a plant extract often sold in capsules. Some small studies have found that it can help you lose weight, if you have a condition such as PCOS, type 2 diabetes, non alcoholic fatty liver disease, or cardiovascular disease, or metabolic syndrome, but not if you’re already healthy. It may also help with insulin resistance, cholesterol, and blood pressure.
Fiber Supplements for Weight Loss
Fiber is a carbohydrate found in many foods we eat such as whole grains, fruits, and vegetables. Soluble fiber—the type that dissolves in water—is thought to help with weight loss in several ways. It can regulate your blood sugar and hunger hormones, and may help you stick to your diet. While it’s best to get your fiber from food, supplements may help you fill the gap if you struggle to get the recommended 25 to 30 grams of fiber per day. However, taking too much can cause bloating, gas, and diarrhea. Start with smaller doses and increase over time.
Capsaicin for Fat Burning
Capsaicin, the chemical that makes spicy peppers spicy, is thought to help with weight loss, but the evidence for this is mixed. Some studies show small reductions in body weight, while others show no change. Capsaicin comes in many forms including capsules and skin patches. It can irritate your skin and mucous membranes, and, if taken in very large quantities (more than 100 mg per kilogram of your body weight), can cause peptic ulcers and even cancer.
Inositol for Diabetes and Weight Loss
Inositol is similar to glucose, and is often found in foods like beans, seeds, and citrus fruits. It can help manage blood sugar and regulate hormones. It is often used by women with polycystic ovary syndrome (PCOS), which can impact both fertility and insulin levels. There’s some evidence it can help with weight loss if you are overweight or struggle with obesity, though the research isn’t as strong for this as it is for controlling blood sugar.
Golo for Weight Loss
Golo is a proprietary blend of herbs and minerals thought to help with weight loss. Among its ingredients, it contains two supplements mentioned above: berberine and inositol. While the company touts studies proving that the supplements are both safe (even if you’re taking any other type of medication) and effective, these studies were small and funded by the company.
Can Caffeine Help with Weight Loss?
Drinking about three cups or so of coffee may help rev up your metabolism to burn a few more calories, but it’s important to keep in mind that we build up a tolerance to caffeine. That means that it may help reduce fat at first, but gradually your body will become less sensitive to it, and taking larger and larger quantities can put you in danger of feeling jittery and anxious. It can raise your blood pressure, especially if it’s already high. Plus, you can experience withdrawal symptoms like headaches, irritability, and difficulty focusing if you stop using it.
A Few Key Points About Caffeine and Weight Loss
- Caffeine seems to help speed up metabolism, temporarily.
- Over time, you will build up a tolerance.
- Caffeine, like other drugs, comes with side effects and if you consume too much, you may feel uncomfortable. In extreme cases, it can be dangerous. For example, it could cause an irregular heartbeat
- Sugary and calorie-laden drinks such as sodas and flavorful lattes will likely negate any weight loss from the caffeine.