22
Supplements and Functional Foods
Common Functional Foods
Mechanism of Action Effects Side Effects
Dietary fiber
May increase sense of
fullness with meals,
delay carbohydrate
absorption, reduce
fatty liver, and increase
insulin sensitivity.
While increased
fiber may increase
satiety and marginally
decrease percent body
fat, reported weight
loss is inconsistent.
Viscous fiber may
promote mild weight
loss.
Some patients may
experience abdominal
bloating or flatulence.
Prebiotics
While they may
include non-
carbohydrates,
prebiotics usually
contain indigestible
oligosaccharides
(e.g., f ructo-
oligosaccharides)
that may stimulate
intestinal growth
(colonic lactobacilli
and bifidobacteria),
which may promote
a microbiome
conducive to weight
loss.
Some human studies
support weight loss.
Weight loss most
consistently reported
in rodents.
Bloating, flatulence
Probiotics
Bacteria such as
lactobacilli (found in
yogurt, dairy products,
and sauerkraut) may
provide protection
against unfavorable
yeast overgrowth and
pathogenic bacteria.
Some human studies
support weight loss.
Weight loss most
consistently reported
in rodents.
Generally safe, small
risk of systemic
infection in at-risk
individuals.
Caffeine with or without plant extracts
May reduce hunger,
increase fat oxidation,
and improve alertness.
Some studies suggest
minor weight loss with
caffeine-containing
foods and products.
High doses can cause
anxiety, tremors,
cardiac dysrhythmias.