Protein for Weight Loss: Benefits, Research & How Much Do You Need?

For Mima Mendoza, a 34-year-old project manager in Severna Park, Maryland, prioritizing protein has become central to her meal planning. She has shifted away from relying on large portions of white rice and now focuses on incorporating eggs, Greek yogurt, fish, and chicken into her diet.

A Long History of Protein Focus

Mendoza reports feeling more satisfied and less prone to snacking since increasing her protein intake, and believes it has aided in maintaining her weight after discontinuing a weight loss medication in October. The idea of protein’s unique ability to promote fullness and support weight loss isn’t new. As early as 1933, a doctor promoted a high-protein, lean meat diet as effective for weight management in an article published in The Times.

Did You Know? In the 1970s, a high-protein drink made from collagen was touted as a “revolutionary” weight loss aid, with some claiming it helped people lose an average of 20 to 25 pounds in a month.

Throughout the decades, interest in high-protein diets has fluctuated. In the 1970s, a collagen-based drink was marketed for rapid weight loss. Today, protein-enriched products are widely available, and high-protein diets and supplements are prevalent on social media. Notably, new federal dietary guidelines released in January recommend increased protein consumption for Americans, citing appetite regulation and weight management as key benefits.

The Science Behind Protein and Appetite

While the concept of protein’s benefits is gaining traction, experts caution against overstating its effects. Stuart Phillips, a professor of kinesiology at McMaster University in Canada, acknowledges protein’s role in appetite control and weight loss but suggests the advantages have been “oversold” by influencers. Research, while limited in scope, suggests a consistent pattern.

A 2020 review of 49 studies indicated that participants generally felt more satisfied and less hungry after consuming protein-rich meals and snacks compared to those with lower protein content. These meals also appear to influence hormone levels, reducing ghrelin (a hunger hormone) and increasing hormones like GLP-1, which promote feelings of fullness. Protein may slow the movement of food through the digestive system, contributing to prolonged satiety.

Expert Insight: While high-protein meals can influence feelings of fullness for approximately three to four hours, research doesn’t consistently demonstrate a reduction in overall food intake at subsequent meals or over extended periods.

However, these effects are not long-lasting, typically lasting only three to four hours. Research suggests that simply increasing protein intake doesn’t automatically translate to reduced overall calorie consumption, according to Richard Mattes, a professor of nutrition science at Purdue University in Indiana. Factors like mood, genetics, and the surrounding food environment also play a significant role in eating habits.

Protein and Weight Management

The evidence regarding the impact of high-protein diets on weight loss and maintenance is mixed, but suggests a modest benefit. A 2021 review of 37 clinical trials found that individuals following higher-protein diets for an average of eight months lost approximately 3.5 more pounds (1.58kg) than those on lower-protein diets. A 2019 review also indicated that higher-protein diets may help minimize weight regain after initial weight loss, when followed for three to twelve months.

Digesting protein requires more energy than digesting carbohydrates or fats, which may contribute to weight management. Prioritizing protein during weight loss may help preserve lean muscle mass. However, Stuart Phillips emphasizes the importance of calorie awareness and resistance training to effectively conserve muscle during weight loss, recommending 1.2 to 1.6 grams of protein per kilogram of body weight.

Frequently Asked Questions

What are some examples of filling meals that prioritize protein?

Dr. Halliday suggests aiming for 20 to 30 grams of protein and at least eight grams of fibre per meal. Examples include scrambled eggs with vegetables and whole-grain toast, lentil soup with bread, or a grain bowl with chicken and roasted broccoli.

Is it best to get protein from whole foods or supplements?

Dr. Leidy recommends obtaining protein from whole foods, as protein shakes and bars are often digested more quickly and may lack the beneficial balance of nutrients found in whole food sources.

How important is fibre in conjunction with protein?

Julia Lloyd emphasizes the importance of fibre alongside protein for sustained fullness and overall health. While most Americans consume enough protein, only about 6 per cent meet their daily fibre requirements, and adequate fibre intake can reduce the risk of various health issues.

Considering all factors, could a mindful approach to protein intake, combined with a balanced diet and lifestyle, be a sustainable strategy for managing appetite and supporting overall well-being?