Losing Weight: Evidence-Based Advice

In my sixteen years of family medicine, I think the most frustrating disease I treat is obesity. It’s frustrating because as a doctor I feel great compassion for these patients, trying so hard to lose weight, and yet I feel almost shameful that as a primary care physician I can’t offer much in terms of medicines to help. And now that I’m back in the USA after ten years in China, I’m very concerned that America’s struggle is even worse, with more than two thirds overweight or obese. So now, driven to seriously tackle this epidemic, I’ve scoured the literature for the most up-to-date, evidence-based advice on losing weight. Please feel free to print and share this.

Surgery

Let me jump right in to perhaps the most controversial point: I think that many, many more people should consider weight loss surgery. It literally is the most effective way not only to permanently cause weight loss, but it also literally can put diabetes in remission, lower your overall death rates, and lower your heart disease risks. A huge percentage of people can stop taking diabetes medicines after surgery. Don’t believe me? Feel free to read up on it, including a 2015 meta-analysis from JAMA, and the Cochrane library review from 2014. There are three major options:

  • Sleeve gastrectomy: This involves stapling off much of the stomach, leaving around 25% of the stomach. Average weight loss is 56%. This is now the most popular of the three.
  • Roux-en-Y gastric bypass: This is the most radical surgery, with the most complications, but also the most effective, with a weight loss up to 67%
  • Adjustable gastric banding: This involves putting a flexible silicone band around the top of the stomach, which essentially limits intake of food and makes you feel full with less food. The average weight loss for this is 44%, less than the other surgeries, and is now less commonly done.

Of course there are risks to these surgeries, and weight loss is disappointing for many afterwards. But in general, this is a far, far better option than the usual lifestyle struggles leading to maybe 10-20% loss at the most, with many gaining the weight back, and still having diabetes and other diseases. In fact, a recent 5-year study comparing weight loss surgery to lifestyle interventions showed a clear winner in the surgery group, with far more people losing much more weight, as well as putting diseases like diabetes in remission — totally stopping insulin injections and diabetes pills.

I seriously hope many people, especially in the high-risk categories, make an appointment with your local bariatric surgery teams and just talk with them, to discuss your options. If you’re in my Swedish system here in the Seattle area, you can sign up for their weight loss seminar and hear them out.

In terms of who should consider bariatric surgery, the current recommendations are:

  • Everyone — and I mean everyone — with a BMI (Body Mass Index) over 40, even without any other medical conditions, should consider bariatric surgery.
  • Anyone with a BMI 30-40 with diseases such as diabetes, high blood pressure, high cholesterol, sleep apnea, or severe arthritis, can also greatly benefit. Insurance companies usually would cover it if your BMI is over 35.

Do you know your BMI? A BMI over 25 is overweight, over 30 is obese. Here’s a BMI calculator from Google.

Prescription Medicines

My second main point, and perhaps even more controversial among physicians, is that prescription medicines can also help with weight loss. There now are four prescriptions and one OTC supplement which actually are FDA approved for weight loss, and these expanding choices are encouraging for us family physicians on the front lines. Most work by decreasing your hunger urges. All have side effects, of course, and weight loss varies from 7-12% on average, and people often regain the weight after stopping. But since even a 5% reduction in weight loss can greatly help reduce risks for diabetes, heart disease and arthritis, I think these are definitely worth considering, and I’m using more and more of these in my practice. I strongly suggest interested people (and doctors) read the 2016 meta-analysis in JAMA, comparing all five. The take-home message from this review is as follows:

  • The medicine phentermine/topiramate (Qsymia) is the most effective at weight loss, losing an average of 8.8 kg over a year, with side effects in the middle of the pack. This is currently my first choice for many. But one side effect is severe: birth defects, so all younger women have to take birth control and get monthly pregnancy tests while on this.
  • The combo medicine naltrexone/bupropion (Contrave) was less effective than Qsymia, with an average 5.0 kg weight loss, and more side effects — and also some debate about its safety with heart disease.
  • The OTC medicine orlistat (Xenical/Alli) is the least effective (2.6 kg weight loss), but has relatively fewer severe side effects (stomach issues), and also is the only one available without a prescription. You take it with each meal, and it decreases fat absorption.
  • The diabetes medicine Liraglutide (Saxenda) is second most effective for weight loss (5.3 kg), but has the most side effects. But it’s certainly a great option for those who have type 2 diabetes.
  • Lorcaserin (Belviq) has the least side effects but was second to last in effectiveness (3.2 kg weight loss).

Who’s a candidate for these prescription medicines? The FDA says that anyone with a BMI over 30, regardless of any illnesses, and also those with BMI 27-20 with risks (the usual ones mentioned above) could benefit from trying these medicines, at least for three months to see if you can get to 5% weight loss. If you do, great! Keep going! Hopefully your insurance will cover the cost (many do not).

Besides these medicines, I should also mention metformin. This common prescription medicine for type 2 diabetes also has the great side effect of weight loss, and while the overall loss is less than 5% in the studies, and thus is not FDA-approved for weight loss, it’s still a fantastic first choice for pre-diabetic people who are overweight. The famous Diabetes Prevention Program showed how even after ten years, the overweight group who took metformin 850 mg twice a day had an impressive 18% reduction in developing diabetes. (That’s impressive, but not nearly as impressive as the 34% risk reduction in the group that stuck to lifestyle changes: weight loss of 7%, 150 minutes a week of exercise, and diets focused on fewer calories and less fat.)

Diets

And now we finally arrive at the third controversial issue: diets. There’s so much overwhelming confusion out there, but I like to simplify it a lot by saying that it’s not so much what you eat, but how much you eat. In other words, calorie restriction is key. If you want to lose a pound a week, you need to eliminate 500 calories each day. This is basic biochemistry. (check out your specific needs using my weight loss calculator at the top right of this article). If you can do this daily calorie restriction, especially by decreasing simple carbs, great! Keep going!

But there’s an interesting newer option you may have heard about, called intermittent energy restriction (IER; the 5:2 diet). This has been trendy since 2013, with a BBC documentarybest selling book, and a British study showing how a twice a week regimen of cutting your calories (especially carbs) had similar or better results for insulin resistance and body fat than the group that followed daily calorie restriction. When we fast, even if only for 12-16 hours (nothing between dinner and lunch the next day), insulin resistance improves and fat starts to get reabsorbed. A recent review of all IER studies showed that the evidence for IER is promising — but still premature to fully endorse, with much more to learn about which pattern is most ideal, as well as long-term effects. Also, people who aren’t overweight and are trying this actually have a lot more side effects than benefits.

Otherwise, in terms of “diet”, it’s just overwhelming out there for people searching for the “right one”. An excellent review article this year does detail quite convincing evidence that a low-carb high-fat Atkins-style diet not only reduces the hunger urge, but also has clear benefits in insulin resistance, cardiac markers, and weight loss. The DASH diet really does help to lower blood pressure and weight, and the Mediterranean diet also seems to help with heart disease and some weight loss.

But again, the main issue for all of this diet talk is to focus not on food categories, but food quantity. It’s simple biochemistry: you have to have less energy intake to lose weight. Or you could increase energy output, which leads us to:

Exercise

For decades, the usual doctor spiel is to get 150 minutes a week of moderate exercise. But that hasn’t really translated into any meaningful changes nationally, has it? So here’s where another trendy (uh oh) regimen is gaining popularity, mostly because the growing research is impressive. It’s called High Intensity Interval Training (HIIT), and it basically means you go all out for 30-60 seconds on any activity, getting to maximum exertion, then take a few seconds break, then do another all-out effort, etc etc. You do this 15 minutes tops, twice a week only (typically). Check out an example in the image below from a New York Times article about a 7-minute workout, which I also blogged about in my New York Times column in China. This HIIT routine is great because it requires zero fancy equipment, and you can do it absolutely anywhere. Click here to access the online workout app.

The 7 Minute Workout. Source: New York Times

Supplements, Diets and Herbals:

This topic is actually less controversial for me, mostly because there’s an easy answer: most of those supplements have almost no hard evidence that they work well. I’m not confident enough about recommending any of the trendy ones, and that includes CLA, chromium, 5-HTP, and garcinia. I’m sure many of you are already taking some of these. You’re welcome to read the evidence, including some excellent supplement reviews by the Natural Medicines Database (paid);  The Encyclopedia of Natural & Alternative Treatments (free); The Cochrane Library; and The National Center for Complementary and Integrative Health (NCCIH).

Personally I’d much rather have my patients focus not on supplements but on calorie restriction. I’d also rather give them one of the prescription medicines above, which all have more evidence than any supplement.

If you must choose a supplement, at least you could try that OTC Orlistat with meals. And you could also consider soluble fiber such as blond psyllium. Used especially for constipation, it also helps lower cholesterol, control diabetes a tiny bit, and also help a bit with weight loss. You’d take it with food, and it absorbs fat from that meal. In fact, it’s now recommended that Orlistat users also take blond psyllium with each dose of Orlistat, as it prevents some of those unfortunate gastric effects.

Yogurt is also one of my favorite recommendations, not just for the way the probiotics help our microbiome and immune system, but also because the literature shows that yogurt helps to manage weight loss and waist circumference. I actually prefer higher fat than the low fat versions, and adding fresh fruit to non-sweetened yogurt is a great way to start your day. Add a pack of instant oatmeal, microwaved with soy milk, and you’ve got a healthy and filling breakfast.

Stand Up!

Did you know that sitting all day at work literally is harmful to your health? Recent data, including this 2015 meta-analysis of sedentary lifestyles, shows that the more you sit, the higher your risks for heart disease, obesity, diabetes and overall death rates. I just ordered a standing desk for my office! Here are more tips on how not to be a couch potato.

Use Smaller Plates

Americans definitely have suffered “portion distortion” over decades, as sizes for all types of food creep up and up. Remember how soda machines used to carry 12 ounce cans, and now all have 20 ounce bottles? How about a small popcorn at the movies? If we can’t control these external factors, at least at home we can control portion size, and one interesting step is to replace all of your usual large dinner plates with smaller plates, like the appetizer or salad plates. Recent studies, including the 2016 meta-analysis, do show that when people switch to smaller plates, they actually eat less. How easy is that?

Keeping It Off

It’s actually not super hard to lose weight — it’s keeping it off that’s the problem for most. Unfortunately, that’s a totally normal problem because our “hunger hormones” ghrelin and leptin reset to a new balance when we gain weight, and when we lose that weight, that hormone imbalance doesn’t reset well to the lower weight, and it thinks “I’m starving!” and compels you to eat more. Some tips to control this include healthy carbs, fiber, yogurt and protein (and not a high fat diet). Also, getting a good night’s sleep literally helps to reset those hunger hormones (that’s one reason why people with sleep apnea are at risk for gaining weight).

And for those who are in the higher obese categories with BMI over 35 or 40, gastric bypass surgery actually can permanently improve some of that hunger urge. How? Removing the top of the stomach in these surgeries removes the stomach tissues that secrete grehlin; less grehlin = less hunger signals = less eating = weight loss. That’s another important reason why I urge people to consider weight loss surgery.

My Bottom Line

After writing this article, I personally feel much more empowered as a doctor to help my patients lose weight. There are a lot more options than I had realized, and I’m definitely giving all of my overweight patients this article, and I look forward to working closely with my patients to help them lose weight in a healthy and permanent way. And hopefully I’ve helped you, as well!

Good luck!


Follow me on Facebook: @BainbridgeBabaDoc
Photography: www.richardsaintcyr.com

2 thoughts on “Losing Weight: Evidence-Based Advice”

  1. Hi. It’s really unexpected that you don’t also talk about the quality of food that is eaten. Surely sugar should be listed as a main culprit of weight gain. Sugar and salt are present in large quantities in the diet of people in the US.

    1. No, actually sugar isn’t the main culprit; sugar is a carb, and it’s the total carbs in people’s diet that is probably the biggest culprit. Carbs in breads, pastas, rice — Americans eat a huge amount of them. Simple sugars of course add to weight, like sodas. By the way, the average diet in China has far more salt than in America! It’s all the sauces and preserved foods…

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