Translating medical guidelines to make personal health decisions, particularly for something like weight loss, has always been challenging, and now the American Medical Association has changed its policy regarding body mass index, telling doctors to deemphasize the role of BMI in clinical practice.

Obesity medicine physician Scott Hagan from the University of Washington explains some of the shortcomings of using BMI as a general guideline for individuals and how it “cannot provide doctors with precise information about the portion of body weight composed of body fat, nor can it tell us how that fat is distributed in the body,” which is critical to understanding health risks. He writes about some of the alternative measurements the AMA now recommends in addition to BMI.

This week, weather stories are dominating headlines, with a heat dome covering the Southern U.S. and wildfires causing air quality problems in large parts of the country. Atmospheric scientist William Gallus from Iowa State University describes the conditions that allow these areas of high pressure to take hold, as well as the dangerous health risks to people. In an article written earlier in the month, climate scientist Drew Shindell explains the multiple harms from air pollution and why tackling air pollutants has a direct impact on both human health and climate change.

It’s rare that we publish stories about mathematics, in part because the knowledge needed simply to understand the work is beyond most people without advanced degrees. But this article on solving the nearly 400-year-old puzzle of Fermat’s last theorem is a fun story showing how obsessed researchers can stay at a problem – sometimes for decades – and how science often advances by gaining insights from disparate fields of research.

Also in this week’s science news:

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Body mass index has been the standard measure to classify obesity and overweight for decades. kaipong/iStock via Getty Images

BMI alone will no longer be treated as the go-to measure for weight management – an obesity medicine physician explains the seismic shift taking place

Scott Hagan, University of Washington

Overreliance on BMI as a measure of weight and health has deepened inequities and led to inaccuracies and overgeneralizations.
Andrew Wiles, the mathematician who presented a proof of Fermat’s last theorem back in 1993, stands next to the famous result. AP Photo/Charles Rex Arbogast

Proving Fermat’s last theorem: 2 mathematicians explain how building bridges within the discipline helped solve a centuries-old mystery

Maxine Calle, University of Pennsylvania; David Bressoud, Macalester College

In 1993, a British mathematician solved a centuries-old problem. But he couldn’t have done it without the help of many other mathematicians, both historical and modern.
As of June 20, 2023, 64% of the U.S. corn crop faced moderate or more intense drought. Jim Watson/AFP/GettyImages

What is a flash drought? An earth scientist explains

Antonia Hadjimichael, Penn State

Flash droughts can develop within a few weeks, causing water shortages, damaging crops and worsening fire risks.

 

Words from Guy Kawasaki: The Conversation is rock-solid nonprofit journalism. I'm here to launch a mission, and I want you to join me. Let's rally our support for The Conversation during its summer fundraising drive! I'm pushing my chips because this is a cause worth betting the house on.

 

What is a heat dome? An atmospheric scientist explains the weather phenomenon baking Texas and forecast to expand

William Gallus, Iowa State University

Heat domes are a dangerous part of summer weather.

The folly of making art with text-to-image generative AI

Ahmed Elgammal, Rutgers University

Visual artists draw from visual references, not words, as they imagine their work. So when language is in the driver’s seat of making art, it erects a barrier between the artist and the canvas.

Lab-grown meat techniques aren’t new – cell cultures are common tools in science, but bringing them up to scale to meet society’s demand for meat will require further development

André O. Hudson, Rochester Institute of Technology

Cell cultures are common tools in biology and drug development. Bringing them up to scale to meet the meat needs of societies will require further development.

Titan submersible disaster underscores dangers of deep-sea exploration – an engineer explains why most ocean science is conducted with crewless submarines

Nina Mahmoudian, Purdue University

Dramatic improvements in computing, sensors and submersible engineering are making it possible for researchers to ramp up data collection from the oceans while also keeping people out of harm’s way.

Do you crush microbes when you step on them?

Ashok Prasad, Colorado State University; Kenneth F. Reardon, Colorado State University

You can squash small bugs by stepping on them, but can you crush even tinier microorganisms like viruses and bacteria? It turns out that you’d need to apply a lot of pressure.

Processing and grieving an ongoing loss – such as a child with a devastating injury or disability – does not fit neatly into traditional models of grief

Brad Phillips, West Virginia University

Letting go of what could have been is a critical step in handling ambiguous loss.

3M offers $10.3B settlement over PFAS contamination in water systems – now, how do you destroy a ‘forever chemical’?

A. Daniel Jones, Michigan State University; Hui Li, Michigan State University

PFAS can be filtered, but getting rid of the chemicals is a monumental challenge. A biochemist and soil scientist explain.

The digital future may rely on ultrafast optical electronics and computers

Mohammed Hassan, University of Arizona

A researcher explains developments in using light rather than electrons to transmit information securely and quickly, even over long distances.