Optimal Protein Podcast with Vanessa Spina

More Protein, More Fat Loss? | Dr. Jose Antonio

Mar 16, 2026

Dr. Jose Antonio, sports nutrition scientist and co-founder of the International Society of Sports Nutrition, is known for protein overfeeding research. He discusses why extra protein did not cause fat gain. Short takes on protein's appetite-suppressing and calorie-burning effects. Conversation covers preserving muscle during dieting, evolving protein guidelines, and practical macronutrient strategies for athletes.

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ANECDOTE

College Bodybuilder Sparked Protein Overfeeding Study

Jose Antonio tested extreme protein overfeeding in trainees, asking some to consume ~4.4 g/kg mostly via shakes for 8 weeks.
Many dropped out; the group that stayed did not gain fat despite eating far more calories.

INSIGHT

Protein Overfeeding Often Reduces Appetite Not Increase Fat

Overeating protein alone tends not to cause fat gain because it suppresses appetite and raises energy expenditure.
Jose Antonio observed personally that extra protein killed his appetite, leading to spontaneous lower calorie intake.

ADVICE

Eat More Protein When Your Goal Is Fat Loss

For preserving muscle and maximizing fat loss, aim higher than minimal protein: ~3 g/kg can help lose fat while maintaining lean mass.
If the goal is only muscle gain, ~2.2 g/kg (1 g/lb) may suffice, but higher protein benefits fat loss.

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In this episode of the Optimal Protein Podcast, Vanessa sits down with sports nutrition scientist Dr. Jose Antonio, one of the world's leading researchers on protein metabolism and body composition.

Dr. Antonio is widely known for his groundbreaking protein overfeeding studies, which found that participants consuming extremely high protein diets did not gain body fat — and in some cases actually lost more fat — even while eating more calories.

In this conversation, Vanessa and Dr. Antonio explore the fascinating metabolic reasons why protein behaves differently in the body, including its thermic effect, impact on satiety, and role in preserving lean mass during fat loss.

They also discuss the newly evolving protein recommendations, how protein interacts with carbohydrates and fats in the diet, and why certain athletes may benefit from lower carbohydrate approaches depending on their sport and metabolic demands.

If your goal is fat loss, body recomposition, or maintaining muscle while dieting, this episode offers a deep dive into the science behind why prioritizing protein can be such a powerful strategy.

In This Episode

• Why protein overfeeding studies showed more calories did not lead to fat gain

• The metabolic reasons protein calories behave differently in the body

• How high protein intake supports fat loss and lean muscle preservation

• The science behind the thermic effect of protein

• Why newer protein recommendations are increasing

• How protein, carbohydrates, and fats interact to influence body composition

• Why certain athletes may benefit from lower carbohydrate strategies

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The content provided in this podcast is for informational purposes only and should not be construed as medical advice. Consult with a healthcare professional before making significant changes to your diet or exercise regimen.