Chapter 3: Energy balance, body comp & PA Flashcards
% of adults & % of children considered overweight or obese
70%, 17%
Physical activity lowers the risk for ________# cancers regardless of weight status
13
A wt gain of only ______ lbs/kg beginning in early adulthood can increase the risk for cancers related to overweight/obesity
11 (5 kg)
*Note wt gain is most concerning in adult life, especially post menopause, for breast cancer risk
Intentional weight loss helps to reduce cancer risk for these 2 cancers especially
Breast & endometrial
mechanisms: reduced insulin & IGF1, estradiol & inflammation
_________ leads to the largest & most sustained weight reduction
Bariatric surgery. This reduces cancer risk, especially in women.
Define Calorie Restriction
A chronic reduction of energy intake by ~30% without incurrence of malnutrition
Research of calorie restriction on cancer
Decreases glucose levels & factors stimulating cell division. Promotes autophagy-mediated recycling of cell components & clearence from damaging factors that influence tissue homeostasis from tumorigenesis
*most research done in prevention on animals. human studies yet to reflect whether CR affects cancer rates
Higher level of physical activity is associated with decrease cancer risk, especially these 3 cancers
Breast, endometrium, colon
PA recommendations for cancer prevention
American Cancer Society: 150-300 minutes of moderate exercise or 75-100 minutes of vigorous intensity (or combination). 60 mins of mod/vig for children.
WCRS/AICR: Be active DAILY. At least 150 minutes of moderate PA or 75 minutes of vigorous intensity weekly.
American College of Sports Medicine: At least 30 mins of mod-vigorous 5x/week (2.5 hours). Muscle strengthening at least 2 days/weel (8-12 reps, 1-3 sets)
National Comprehensive Cancer Network: none
Moderate versus vigorous exercise
Moderate - can talk but not sing (water aerobics, tennis doubles, brisk walking)
Vigorous - requires too much effort to talk (running, walking uphill, swimming laps, heavy gardening, tennis singles)
PA recommendations during cancer treatment
ACS: Individualize. Return to baseline activity ASAP after diagnosis and avoid being sedentary.
WCRI/AICS: Daily PA
ACSM: Avoid inactivity. Return to normal PA ASAP. Conduct pre-exercise assessment and tumor site-specific assessment as needed
NCCN: Follow ACS & ACSM guidelines
Special consideration for PA with severe anemia
Delay exercise other than ADLs until anemia improves
Avoid these areas of exercise w/ compromised immune function
Public gyms/pools until WBC return to safe levels. Avoid for 1 year after bone marrow transplant
Survivors experiencing severe fatigue are encouraged to do ______ minutes of light exercise daily
10 minutes
Survivors undergoing radiation should avoid exposing irradiated skin to ______
Chlorine
Survivors with ______________ or _____________ should avoid pool, lake, ocean water, or other microbial exposures that may/ result in infection.
Avoid resistance training of muscles in the area to avoid dislodgement.
Indwelling catheters or feeding tubes
Survivors with multiple comorbidities should ________
Consider program modifications in consultation with physician
Survivors with significant peripheral neuropathies or ataxia may do better with _______________ than treadmills
Stationary bikes
Long term cancer survivor recommendations for physical activity
ACS: at least 150 mins/week + strength training at least days/week
WCRF/AICR: Same as prevention
ACSM:
-ages18-64, 150 mins/week of moderate-intensity PA or 75 mins/week of vigorous. Muscle strengthening at least 3 days/week for each major muscle group. Stretch major muscle groups & tendons.
NCCN: 150 mins moderate-intensity PA or 75 mins/week vigorous. Strength training 2-3/week including major muscle groups. Stretch at least 2x/week. Avoid prolonged sedentary behavior. Resistance training as prescribed
-Frequency: 2-3x/week, wait 48 hours between sessions
-Intensity: 2-3 sets of 10-15 reps/set, increase weight as this becomes easy
-Time: 20 minutes per session
-Rest: 2-3 minutes between sets & exercises
BMI formula
weight (kg)/height (meters sq)
*most common too for determining obesity but poorly reflects body composition
Esp w/ cancer, body composition is more important
*waist/hip ratio may be a better option
Best direct measurement tool for quantifying skeletal muscle
CT - standard of care, non-invasive & precise. Third lumbar vertabra cross-sectional is the area chosen to best correlate with body composition.
(MRI is great but mostly reserved for research setting)
Obesity-related mechanisms in cancer occurrance
Visceral fat is metabolically active and plays a large role
-increase insulin resistance & IGF1
-increased inflammation
-leptin at higher levels
-decreased adiponectin
-increased estrogen (produced mostly through adipose post-menopause, ovaries pre-menopause)
Physical activity related mechanisms related to cancer
Not fully understood
-Indirect by reducing obesity
-Lowering chronic inflammation
-Improving immune function
-Activating peristalsis (colon ca)
Define cachexia
A metabolic syndrome driven by inflammation and characterized by muscle loss, with or without the loss of fat mass
Multi-factorial and cannot be fully reversed by conventional nutrition support
Leads to progressive functional impairment
Cancer cachexia is most prevalent in these 7 cancer types
- lung
- pancreatic
- H&N
- prostate
- esophageal
- colorectal
- gastric
A diagnosis of cancer cachexia is made using one of the following 3 criteria
- Weight loss of > 5% over the past 6 months in the absence of starvation
- BMI of <20 and any degree of weight loss >2%
- Appendicular skeletal muscle index indicative of sarcopenia <7.26 for men, <5.45 for women AND weight loss of >2%
3 stages of cancer cachexia
- Precachexia - weight loss, anorexia. Progression depends on cancer type, inflammation, PO intake, lack of response to cancer therapy
- Cachexia - one of the 3 definitions + reduced food intake & presence of systemic inflammation
- Refractory “resistant” cachexia - active catabolism, management of weight loss not possible, very advanced or rapidly progressive cancer, unresponsive to therapy
(typically last 3 months of life)
Define sarcopenia
Severe muscle depletion. First described as “frailty syndrome.”
Occurs 15% in healthy people, 40-50% in cancer patients. Used as a prognostic factor
Associated w/ poor performance and chemo toxicity
Sarcopenic obesity
Combination of low muscle mass & high adipose tissue. Often overlooked at being at-risk for malnutrition.
Define intermittent fasting
A type of calorie restriction in which pts go 16-48 hours with little to no energy, followed by periods of normal food intake, occurring on a recurring basis.
In cancer patients, this may improve metabolism & reduce inflammation with fewer negative effects
(i.e. complete fasting every other day, 70% energy restriction every other day)
Define periodic fasting
Fasting or fasting-mimicking diet for 2-21 days
Potential benefits of fasting
-May improve chemotherapy treatment, partially d/t impact on circadian rhythm
-May improve radiosensitivity of mammory tumors
-May reduce side effects
*more human studies needed
Define Time-Restricted Feeding
Food intake restricted to 8 hours/day or less
Obesity paradox with cancer
Emerging studies have found that elevated BMI is associated with improved survival compared with normal weight patients
This is only found with overweight & mild obesity (class I) having a protective effect. Class 2 & 3 are associated with worse outcomes.
Ideal weight loss programs should include
-at least 6 months including diet, PA, and behavior modification
-ideally on-site & frequent sessions
-Group or individual by a trained interventionalist
Define medically-based weight loss program
Includes an oncology dietitian or weight-loss clinic (may be covered by certain insurance yet not usual specific for cancer)
Highly personalized yet limited access d/t costs & lack of coverage. Some cancer centers may offer free of charge
Define community-based weight-loss programs
- Not for profit - cancer specific, typically with an RDN or other health specialist. Typically low cost or free of charge, i.e. LIVESTRONG
- Work-site - employers may include programs for their cancer survivors as part of their health & wellness plan but this isn’t widely available or known. Likely no-cost to the participants
- Commercial - convenient, usually participant pays, may be costly and not cancer specific (i.e. weight watchers)
Define home-based weight loss programs
- Cancer-specific programs - only available through research studies. Effective & convenient but limited.
- Non-cancer specific - websites, apps, print materials. Convenient but minimal cancer-specific information. May or may not be free.
T/F: PA may counteract changes in body composition associated with hormone therapy
True
Studies have shown benefits of resistance training for breast & prostate cancers
FITT principle for exercise prescription
Frequency
Intensity
Type
Time (duration)
*should also involve a plan for advancement as fitness levels improve
