Screenings after weight loss surgery
Some types of weight loss surgery change how you digest food and absorb nutrients, and MedlinePlus says you will need medical follow-up for the rest of your life. (MedlinePlus) This page lists the follow-up checks guidelines tie to life after bariatric (metabolic) surgery. Checks before surgery are on screenings if you have overweight or obesity. This page covers screening only, not supplements, diet, medicines or the choice of operation.
Lifelong follow-up
NICE says to offer people who have had bariatric surgery a follow-up care package for a minimum of 2 years within the bariatric service, including monitoring of nutritional intake (including protein and vitamins) and mineral deficiencies, monitoring for related health conditions, a medications review and psychological support. After discharge from the bariatric service, NICE says people should be offered at least annual monitoring of nutritional status, shared with primary care. (NICE NG246) The NHS says follow-up usually happens in a weight loss surgery clinic for at least the first 2 years and may then become a check-up with a GP once a year for the rest of your life, with blood tests to check your vitamin and mineral levels and a physical health check. (NHS) MedlinePlus says you will need regular checkups with your provider to follow your weight loss and make sure you are eating well. (MedlinePlus, life after surgery)
The ADA says people who have metabolic surgery should receive long-term medical and behavioral support and routine micronutrient, nutritional and metabolic status monitoring, and should be checked for insufficient weight loss or weight regain at least every 6 to 12 months. (ADA, 2026)
Blood tests and how often
The British Obesity and Metabolic Surgery Society (BOMSS) suggests these checks after surgery: (BOMSS, 2020)
| Test | Who | How often (BOMSS) |
|---|---|---|
| Kidney and liver function | Everyone after surgery | 3, 6 and 12 months in the first year, then at least once a year (BOMSS, 2020) |
| Full blood count and ferritin (iron stores) | Everyone after surgery | 3, 6 and 12 months in the first year, then at least once a year (BOMSS, 2020) |
| Folate and vitamin B12 | Everyone after surgery | 3, 6 and 12 months in the first year, then at least once a year (BOMSS, 2020) |
| Vitamin D and calcium | Everyone after surgery | 3, 6 and 12 months in the first year, then at least once a year (BOMSS, 2020) |
| Zinc and copper | After a sleeve gastrectomy, gastric bypass or BPD/DS | Consider at least once a year (BOMSS, 2020) |
| Selenium | After a gastric bypass or a malabsorptive procedure such as BPD/DS | Consider at least once a year (BOMSS, 2020) |
| Vitamins A, E and K | After a malabsorptive procedure such as BPD/DS | Vitamin A every 3 months, then once a year when stable; vitamins E and K at least once a year (BOMSS, 2020) |
| HbA1c and cholesterol (lipids) | HbA1c if you had diabetes before surgery; lipids if you had high cholesterol | Monitor (BOMSS, 2020) |
What the numbers mean is on complete blood count results, iron test results (ferritin), vitamin B12 test results, vitamin D test: who needs it, kidney test results and liver function test results.
Blood sugar if you had diabetes
The ADA says metabolic surgery often leads to remission of diabetes, and that 35 to 50% of people who first achieve remission eventually see diabetes come back. (ADA, 2026) A consensus report on remission says that after surgery, HbA1c should be checked at least 3 months after the procedure and 3 months after stopping any glucose-lowering medicine, and then no more often than every 3 months and no less often than once a year to confirm the remission is continuing. (Riddle, 2021) It also says people in remission should be advised to have regular retinal (eye) screening, kidney function tests, foot checks, and blood pressure and weight measurement. (Riddle, 2021) See A1c and blood sugar test results, diabetic eye exam results, diabetic foot exam and screenings if you have diabetes.
Bones
The ADA lists osteoporosis, anemia and vitamin and mineral deficiencies among the longer-term risks after metabolic surgery. (ADA, 2026) BOMSS includes vitamin D and calcium in its routine blood tests. (BOMSS, 2020) The NICE, BOMSS and ADA documents above do not set a schedule for bone density scans after surgery; the usual criteria are on bone density test: how often and DEXA scan: what to expect.
Checks in pregnancy
BOMSS says pregnant women who have had bariatric surgery should have nutritional screening during each trimester, including ferritin, folate, vitamin B12, calcium, vitamin D and vitamin A, and that reference ranges change in pregnancy. (BOMSS, 2020) A 2019 international consensus says: (Shawe, 2019)
- women planning pregnancy after bariatric surgery should be screened for diabetes before pregnancy, and during pregnancy should routinely be screened for gestational diabetes
- the oral glucose tolerance test is appropriate between 24 and 28 weeks after a gastric band; after a bypass, sleeve or BPD, it may not be tolerated (dumping) or accurate, so seven-point finger-prick glucose profiles or a week of continuous glucose monitoring between 24 and 28 weeks are suggested instead
- for women whose type 2 diabetes is in remission after surgery, fasting glucose or HbA1c at booking and in the second trimester may add value
- ultrasound monitoring of the baby's growth should be offered to all women with a history of bariatric surgery
See gestational diabetes glucose test results and pregnancy screenings by week.
Mental health
The ADA says to routinely screen people who have had metabolic surgery for psychosocial and behavioral health changes and refer to a qualified behavioral health professional as needed. It says people may be at increased risk of substance use, worsening or new depression or anxiety, and suicidal thoughts after surgery. (ADA, 2026) NICE includes psychological support tailored to the person in the follow-up package. (NICE NG246) See mental health screenings by age.
The usual screenings still apply
Follow-up after surgery adds to your age-based screenings; it does not replace them. Cancer screening, blood pressure, cholesterol and the rest are on screenings by age and gender and cancer screenings by age.
Where they differ:
- How detailed the blood test schedule is. NICE asks for at least annual monitoring of nutritional status after discharge but does not list tests; (NICE NG246) BOMSS sets test-by-test intervals, mostly 3, 6 and 12 months then yearly; (BOMSS, 2020) the ADA asks for routine monitoring without set intervals for nutrients and every 6 to 12 months for weight. (ADA, 2026)
- Which operation. BOMSS adds tests such as vitamins A, E and K and selenium only after malabsorptive procedures such as BPD/DS, (BOMSS, 2020) and the pregnancy consensus treats a gastric band differently from other operations for gestational diabetes testing. (Shawe, 2019)
- Blood sugar after remission. BOMSS says to monitor HbA1c in people who had diabetes before surgery; (BOMSS, 2020) the remission consensus sets the interval at every 3 to 12 months and adds eye, kidney and foot checks. (Riddle, 2021)
Your doctor decides what your result means for you.
Questions people ask
How long is follow-up needed after weight loss surgery?
For life. NICE says to offer a follow-up care package for at least 2 years within the bariatric service, then at least yearly monitoring of nutritional status shared with primary care. The NHS says this may change to a check-up with a GP once a year for the rest of your life, and MedlinePlus says you will need medical follow-up for the rest of your life. (NICE NG246) (NHS) (MedlinePlus)
Which blood tests are done after bariatric surgery?
BOMSS (UK) suggests checking kidney and liver function, full blood count, ferritin, folate, vitamin B12, vitamin D and calcium at 3, 6 and 12 months in the first year and at least once a year after that, with extra tests such as zinc, copper, selenium and vitamins A, E and K depending on the type of operation. (BOMSS, 2020)
Do I still need blood sugar tests if my diabetes went away after surgery?
Yes. A consensus report says HbA1c should be measured no more often than every 3 months and no less often than once a year to confirm a remission is continuing, and that people in remission should still have regular eye screening, kidney tests, foot checks, blood pressure and weight checks. BOMSS says to monitor HbA1c in people who had diabetes before surgery. (Riddle, 2021) (BOMSS, 2020)
How is gestational diabetes checked in pregnancy after a gastric bypass?
A 2019 international consensus says women with a history of bariatric surgery should routinely be screened for gestational diabetes. It says the oral glucose tolerance test is appropriate after a gastric band, but after a bypass, sleeve or other procedures it may not be tolerated (dumping) and may not be accurate, and suggests seven-point finger-prick glucose profiles or a week of continuous glucose monitoring between 24 and 28 weeks. (Shawe, 2019)
Is mental health checked after weight loss surgery?
The ADA says to routinely screen people who have had metabolic surgery for psychosocial and behavioral health changes and to refer to a qualified behavioral health professional as needed. It notes a possible higher risk of substance use, depression or anxiety, and suicidal thoughts. (ADA, 2026)