Every 100 kcal of sweet potato brings 2.2 g of protein. On that measure it ranks 87th of the 105 vegetables in this database and 679th of all 796 foods on the site. Measured by weight instead, its 2.01 g per 100 g ranks 47th in its group.
Only about 9% of the calories in sweet potato come from protein, so it is more of an energy food than a protein food. It is worth eating for other reasons; the protein it adds to a day is incidental.
USDA lists 0.15 g of fat per 100 g of sweet potato, too little for a protein-to-fat ratio to mean much.
Set against oyster mushrooms, another vegetable entry in the database, a serving carries about 0.5 g less protein (oyster mushrooms has 2.8 g per 1 cup sliced).
It is an incomplete protein on its own; pairing it with other plant foods across the day covers the full range of essential amino acids. The serving quoted here is counted by piece at 114 g, and it covers about 5% of the 50 g FDA Daily Value for protein.
Serving sizes
Protein in common portions of sweet potato
Protein and calories in Sweet potato for 100 g, the site serving and USDA household portions.
Portion
Weight
Protein
Calories
100 g
100 g
2.01 g
90 kcal
1 medium (serving used here)
114 g
2.3 g
103 kcal
1 cup
200 g
4 g
180 kcal
1 large
180 g
3.6 g
162 kcal
1 small
60 g
1.2 g
54 kcal
Portion weights are the household measures listed on the USDA record; protein and calories scale from the per-100 g figures.
Amino acids
Essential amino acids in sweet potato
The nine essential amino acids in Sweet potato, per 100 g, per serving and per gram of protein.
Amino acid
Per 100 g
Per serving
mg per g protein
leucine
0.118 g
0.13 g
59
lysine
0.084 g
0.1 g
42
valine
0.11 g
0.13 g
55
isoleucine
0.07 g
0.08 g
35
threonine
0.107 g
0.12 g
53
phenylalanine
0.114 g
0.13 g
57
methionine
0.037 g
0.04 g
18
histidine
0.039 g
0.04 g
19
tryptophan
0.04 g
0.05 g
20
Per-100 g values are the amino acid analysis on the USDA record. The serving and per-gram-of-protein columns are arithmetic on those values; they are not a protein quality score.
SampleWhat goal trends look like after a week
109 g
Average per logged day
4 of 7
Days goal met
71%
Complete-protein share
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Sample figures for one made-up week against a 110 g goal, not your data. Red bars met the goal. Your own log fills this in with Premium.
Related
Other vegetables by protein per calorie
Swap for more protein per calorie
Butternut squash - 2.3 g per 100 kcal, 1.8 g per 1 cup cubes baked
2.01 g. The 1 medium serving used on this page weighs 114 g and so carries 2.3 g.
How much protein do you get per 100 calories of sweet potato?
2.2 g. That figure divides its 2.01 g of protein per 100 g by its 90 kcal per 100 g, so it does not depend on serving size.
Is the protein in sweet potato complete?
No. On its own, the protein in sweet potato is short of at least one essential amino acid; other protein sources across the day fill the gap.
What share of the protein Daily Value is one serving of sweet potato?
About 5%. One 1 medium serving has 2.3 g, and the FDA Daily Value for protein is 50 g.
Figures from USDA FoodData Central record #168483 (Sweet potato, cooked, baked in skin, flesh, without salt), SR Legacy data. USDA data is in the public domain. Values are the published reference figures for that record, not lab measurements for a specific brand or batch.