Tag: Medications for weight loss

Food Addiction and Obesity: How the Brain Is Involved

On By Dr. Scott RennieIn Weight Loss & Metabolic HealthLeave a comment

The human brain gets described as an engineering marvel. Like any product, it ships with vulnerabilities. Evolution built a system for surviving scarcity, and we now run that system in an environment of constant stimulation and engineered food. The mismatch explains a great deal about why obesity and addiction share so much ground.

One useful way to frame it is in terms of failure modes. Sometimes the design itself creates the problem. Sometimes development goes off track. And sometimes a perfectly good brain breaks down under conditions no brain was built for.

Take the design. We evolved to crave calorie-dense food because it was scarce and it kept us alive. Sugar and fat are now everywhere, and those old drives get hijacked. Food companies understand how to exploit them, the same way addictive substances exploit the same reward circuitry. The biology has not changed. The environment has.

Development matters too. Prenatal nutrition, early childhood adversity, and other disruptions shape how the brain handles reward and stress. Analysis of roughly 2,700 children in the NIH-funded ABCD Study found that higher BMI was associated with thinner cortex, particularly in prefrontal regions, and with lower working memory on list-sorting tasks (Laurent et al., 2020). Brain development itself appears alterable in the setting of poor diet and excess weight.

Then there are the extreme conditions. Trauma, chronic stress, and social adversity overwhelm coping systems, and food and drugs become the fallback. Calling that a failure of willpower misses what is happening. The brain is adapting, badly, to circumstances it can’t otherwise handle. It also helps explain why obesity and addiction cluster in groups facing economic hardship and unstable environments.

Dopamine sits at the center of both. Dopamine does more than produce pleasure. It teaches the brain what to attend to and what to repeat. Eat sugar, dopamine surges, the brain takes note. Use a drug, same signal. With repeated exposure, dopamine receptors downregulate (Volkow et al., 2013). Tolerance builds. Soon more sugar or more drug is needed to reach baseline.

Refined sugar is unusually effective in this loop. It spikes glucose fast, drives dopamine release, and slips past satiety signaling. Animal studies show sugar producing binge-like intake patterns and withdrawal signs on removal (Avena et al., Neurosci Biobehav Rev, 2008). In humans, high sugar intake has been linked to memory problems, greater inflammation, and impaired hippocampal function (Kendig, Appetite, 2014). Which is why cutting sugar feels less like breaking a habit and more like breaking an addiction.

So what helps? Supporting the brain at each stage. Protecting the developing brain through prenatal nutrition and limiting early sugar exposure. Teaching children coping skills, protecting sleep, and building activity, all of which strengthen the prefrontal cortex that reins in impulse. Reducing ultra-processed food at home and in schools.

Medications now target this signaling directly. GLP-1 receptor agonists act on satiety hormones in the gut and on brain pathways that regulate appetite. They reset the system rather than substituting for resolve.

Research is moving toward brain-based interventions: neurofeedback, brain stimulation, digital tools that reinforce healthier behavior in real time. The underlying message has not changed. Obesity and addiction are brain-based conditions shaped by biology, environment, and lived experience. Recognizing that changes how we treat and support the people in front of us, without letting anyone off the hook for their own care.

Scott Rennie, D.O.

References:

1. Laurent JS, et al. Associations Among Body Mass Index, Cortical Thickness, and Executive Function in Children. JAMA Pediatr. 2020;174(2):170-177. https://pubmed.ncbi.nlm.nih.gov/31816020/

2. Volkow ND, Wang GJ, Tomasi D, Baler RD. Obesity and addiction: neurobiological overlaps. Obes Rev. 2013;14(1):2-18. https://pubmed.ncbi.nlm.nih.gov/23016694/

3. Avena NM, Rada P, Hoebel BG. Evidence for sugar addiction: behavioral and neurochemical effects of intermittent, excessive sugar intake. Neurosci Biobehav Rev. 2008;32(1):20-39. https://pubmed.ncbi.nlm.nih.gov/17617461/

4. Kendig MD. Cognitive and behavioural effects of sugar consumption in rodents: a review. Appetite. 2014;80:41-54. https://pubmed.ncbi.nlm.nih.gov/24816323/

Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Weight Loss Medications for Kids and Adults Explained

On By Dr. Scott RennieIn Weight Loss & Metabolic HealthLeave a comment

As a physician, I know that treating obesity can be tough. Many families put in real effort with diet and exercise and still don’t see enough progress. When that happens, medication becomes worth discussing. Not for everyone. For the right patient, though, it can make a real difference.

Every price below reflects March 2025, when this was first written, and drug pricing in this class moves constantly, list price, cash price, and whatever a given insurer decides to cover can all diverge sharply, so treat every figure below as a historical marker rather than a current quote.

For children ages 12 and older, there are a few choices. Orlistat, brand name Xenical, blocks fat absorption in the gut. Because it stays in the digestive tract, it doesn’t touch appetite or the brain. The catch is side effects. Eat too much fat on this drug and a kid can get oily stools, gas, frequent bowel movements. A low-fat diet helps. It can still be uncomfortable. The price ran about $50 to $200 a month. The FDA cleared it for ages 12 and up.

Liraglutide, brand name Saxenda, is another option. It mimics a gut hormone called GLP-1, helping with appetite control and slowing stomach emptying. It’s effective, and it also helps blood sugar control, which matters if a patient has insulin resistance. But it requires daily injections, and nausea is common. Vomiting and diarrhea can happen too. Monthly cost usually fell between $1,200 and $1,500 a month. The FDA approved it for kids starting at age 12.

Phentermine combined with topiramate, sold as Qsymia, is approved for adolescents 12 and up who meet obesity criteria. Phentermine reduces appetite. Topiramate curbs cravings. Together they can produce substantial weight loss, especially in patients who struggle with binge eating. Side effects include dry mouth, dizziness, insomnia, and mood changes, and blood pressure and heart rate need regular checks. Cost averaged $200 to $300 a month.

Semaglutide, brand name Wegovy, is another GLP-1 receptor agonist, injected once weekly instead of daily. Clinical studies show it produces impressive weight loss. Side effects mirror other GLP-1 drugs: nausea, vomiting, diarrhea, abdominal pain, constipation. Out-of-pocket cost usually ran $1,300 to $1,600 a month. The FDA approved it for adolescents age 12 and up.

Setmelanotide, or Imcivree, is different from everything above. It targets rare genetic conditions that cause obesity, POMC, PCSK1, or LEPR deficiencies, by restoring hormonal signals that regulate hunger. It’s not meant for most patients, only those with a specific genetic diagnosis. For those who qualify, it can work well. The price tag was steep, though: about $16,000 a month.

For adults, the options broaden, and the prices below are again what things cost in March 2025, not today. Phentermine has been used for decades. It works on the central nervous system to suppress appetite, usually prescribed short-term and paired with diet and exercise. It can be effective, but it may cause insomnia, dry mouth, and a faster heart rate, and it isn’t safe for people with heart disease. The cost was low, around $30 to $60 a month.

Bupropion combined with naltrexone, sold as Contrave, takes a different approach. Bupropion affects brain chemistry to help with appetite and mood. Naltrexone reduces cravings. Some patients feel more energetic on it. Side effects can include nausea, dizziness, and insomnia. Mood changes are possible, so follow-up matters. Cost averaged $200 to $300 a month.

Tirzepatide, marketed as Mounjaro, is one of the newest medications. It activates both GLP-1 and GIP receptors, improving satiety and insulin sensitivity. Given as a weekly injection, it has shown striking results for weight loss. Nausea and diarrhea are the most common side effects, as with other drugs in this class. Costs ran high, around $1,000 to $1,500 a month. At publication it was FDA-approved for type 2 diabetes, not obesity, though already used off-label for weight loss.

A few points cut across all of these. Insurance coverage is unpredictable: some insurers won’t cover these drugs at all, others demand proof that lifestyle efforts were tried first. Close monitoring is essential, because side effects vary. None of these drugs replace healthy habits. They work best stacked on top of diet, activity, and behavior change.

For patients and families, the choices can feel like a lot. Knowing what’s actually available, and what each option costs and asks of you, helps match the right treatment to the right person.

Scott Rennie, D.O.

Sources:

Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.