How much soy is too much?

The recommended amount of soy consumption per day is a controversial issue. Different studies and organizations recommend different amounts. Should we avoid soy altogether? Or perhaps a little bit of soy is good for you? Or can we consume as much as we would like? How much soy is too much?

To find the answers watch this 2-minute video from

What is one serving of soy? [7]

Soy yogurt – 1 cup

Tofu – 3 ounces

Soymilk – 1 cup

Edamame – 1/2 cup

Soy “burger” – 1 patty

Tempeh – 3 ounces

Soy pasta – 1/2 cup (cooked)

Soy nutrition bar – 1 bar

Soy nuts, roasted – 1/4 cup

Soy breakfast patty – 2 patties

Meatless soy crumbles – 1/3 cup

Soy chips – 1 bag

Soy nut butter – 2 Tbsp



Video courtesy of Dr. Michael Greger and


[1] Shu XO, Zheng Y, Cai H, Gu K, Chen Z, Zheng W, Lu W. Soy food intake and breast cancer survival. JAMA. 2009 Dec 9;302(22):2437-43. 

[2] Wu AH, Yu MC, Tseng CC, Pike MC. Epidemiology of soy exposures and breast cancer risk. Br J Cancer. 2008 Jan 15;98(1):9-14. 

[3] Nagata C, Shimizu H, Takami R, Hayashi M, Takeda N, Yasuda K. Dietary soy and fats in relation to serum insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 levels in premenopausal Japanese women. Nutr Cancer. 2003;45(2):185-9. 

[4] Dewell A, Weidner G, Sumner MD, Barnard RJ, Marlin RO, Daubenmier JJ, Chi C, Carroll PR, Ornish D. Relationship of dietary protein and soy isoflavones to serum IGF-1 and IGF binding proteins in the Prostate Cancer Lifestyle Trial. Nutr Cancer. 2007;58(1):35-42. 

[5] Arjmandi BH, Khalil DA, Smith BJ, Lucas EA, Juma S, Payton ME, Wild RA. Soy protein has a greater effect on bone in postmenopausal women not on hormone replacement therapy, as evidenced by reducing bone resorption and urinary calcium excretion. J Clin Endocrinol Metab. 2003 Mar;88(3):1048-54. 

[6] Maskarinec G, Takata Y, Murphy SP, Franke AA, Kaaks R. Insulin-like growth factor-1 and binding protein-3 in a 2-year soya intervention among premenopausal women. Br J Nutr. 2005 Sep;94(3):362-7.