The Best Diet May Vary, New Stanford Research Suggests

For many heading into 2023, weight loss will be at the top of New Year’s resolutions. New research evaluated weight loss on different diet types to see which produced the most benefit.

A new Stanford study evaluated healthy low-carbohydrate and healthy low-fat diets over one year. Researchers discovered unique traits contributing to either short or long-term weight loss.

Currently, obesity is an ongoing health crisis in the United States. According to the Centers for Disease Control (CDC), obesity prevalence in the U.S. between 2017 and 2020 was 41.9%.

Finding the right diet

The study titled Distinct factors associated with short-term and long-term weight loss induced by low-fat or low-carbohydrate diet intervention was published in Cell Reports on December 13, 2022. Over 609 participants were involved in the data,

Stanford researchers highlight weight loss success is difficult to come by. However, remaining disciplined in either a healthy low-carbohydrate or healthy low-fat diet can lead to weight loss in six months, based on the study’s findings.

After a year, minimal dietary differences were associated with long-term weight loss. Researchers believe certain biomarkers of metabolism can predict how successful an individual will be in losing weight in the long term.

During the study, researchers measured the ratio of inhaled oxygen to exhaled carbon dioxide to discover whether carbohydrates or fats served as the primary source of energy in participants.

For example, if on a healthy low-carb diet, one struggles to lose weight, it may be because the body’s metabolism requires a different type of diet to lose weight.

Dalia Perelman is a research dietician and co-lead author of the Stanford research. In a conversation with Stanford Medicine, Perelman notes reducing calorie intake alone is not enough for weight loss.

"We found specific microbiome ecologies and amounts of proteins and enzymes at the beginning of the study period - before people started following the diet - that indicated whether they would be successful at losing weight and keeping it off," Perelman said. “There are people who can be eating very few calories but still sustain their weight because of how their bodies metabolize fuels. It is not for lack of will: It is just how their bodies work."

Obesity in the U.S.

Obesity is growing in the U.S. Last month, the CDC adjusted its body mass index (BMI) due to increased obesity prevalence in children. BMI is a mathematical formula calculating a person’s weight in pounds divided by the square of height in feet. A good BMI score for adults ranges from 18.5–24.9.

Previously the BMI scale was charted as high as 37 for children, but with new data, the scale reaches 60. Childhood obesity is a major area of concern, with 14.7 million children and adolescents affected.

The CDC says obesity can lead to type 2 diabetes, heart disease, and some cancers. There are multiple preventative measures that can be taken to combat obesity.

Healthy eating

The Stanford study shows finding the right diet can be tricky. Until more technology is available to determine which diet may be the best for the individual based on their metabolism, it is important to stick to well-known healthy choices.

Low-carb diets should feature healthy unsaturated fats found in nuts and avocados, versus the fats found in processed meats. Individuals partaking in low-fat diets will want to rely on high-fiber foods including whole-grain bread and beans.

Excluding junk food and sugar-sweetened beverages will help against added calories with little nutritional benefit. Consuming lean meats, low-fat calcium-rich foods, and healthy servings of fruits and vegetables over comfort alternatives is a great start.

Physical activity

The CDC emphasizes that exercise can help extend life span and prevent diseases that come with obesity along with obesity itself. The U.S. Surgeon General recommends for adults 150 minutes of exercise per week and 60 minutes of play per day for children.

The Physical Activity Guidelines for Americans from the U.S. Department of Health note increased health benefits when adults push the 300 minutes per week of moderate-intensity workouts. Also, at least two days of muscle-strengthing is recommended for adults.

When new to physical activity, it is important to start slow as injuries can occur. Stretching before and after physical activity can prevent injuries. Physical activity is a great compliment to individuals seeking results from dieting.

Moderate-intense activities include brisk walking, recreational swimming or water aerobics, yoga, and slow dancing to include a few. More vigorous activities involve running, competitive swimming, tough hikes, high-intensity interval training, and other workouts that increase the heart rate faster than slower forms of exercise.