Table 3.

Sample sizes needed in a cohort design to detect significant associations of genetic variants with BMI change with a power of 80% and a two-sided P of 0.05 by beta coefficient and allele frequency for risk allele

Minor allele frequency
Allelic beta	0.01	0.05	0.1	0.2	0.3	0.4
0.01	>1 000 000	669 216	353 196	198 671	151 367	132 446
0.02	802 722	167 301	88 296	49 665	37 839	33 109
0.03	356 763	74 354	39 240	22 071	16 815	14 713
0.04	200 678	41 822	22 071	12 413	9457	8274
0.05	128 432	26 765	14 124	7943	6051	5294
0.06	89 188	18 586	9807	5515	4201	3675
0.07	65 525	13 654	7204	4051	3085	2699
0.08	50 166	10 453	5515	3100	2361	2066
0.09	39 637	8258	4357	2449	1865	1631
0.10	32 105	6688	3528	1983	1510	1321
0.20	8023	1669	879	493	374	327
0.30	3564	740	389	217	164	143
0.40	2003	414	217	120	91	79
0.50	1280	264	137	75	57	49
0.60	888	182	94	51	38	33
0.70	651	133	68	36	27	23
0.80	498	101	51	27	19	16
0.90	392	79	40	20	14	12
1.00	317	63	31	16	11	9

BMI, body mass index.